User:Mohammad adil/sandbox8545005

The Islamic conquest of Persia led to the end of the Sassanid Persian Empire in 644, Sassanid dynasty in 651 and the eventual extirpation of the Zoroastrian religion in Persia. Sassanid Persian empire was first invaded by Muslims in Iraq in 633 under legendary general Khalid ibn Walid, which resulted in Muslim conquest of Iraq. Following the transfer of Khalid to Roman front in Levant, Muslims eventually lost Iraq to Persian counter attacks. The second invasion of Iraq begun in 635 under Saad ibn Abi Waqqas when after a key victory at Battle of Qadisiyyah Sassanid controll west of Persia was perminently ended. Zagros mountains became a natural barrier and borders between Rashidun Caliphate and Sassanid empire. Owing to continous raids of Persians in Iraq, Caliph umar ordered a whole scale invasion of Sassanid Persian empire in 642 which came to an end with complete conquest of Sassanid empire by mid 644. The quick conquest of Persia in series of well coordinated multi-pronged attacks, operated by Caliph Umar from Madinah several thousand miles from the battle fields in Persia, became his greatest triumph, marking his reputation among the greatest strategists and political genius of history. Most Muslim historians have long offered the idea that Persia, on the verge of the Arab invasion, was a society in decline and decay and thus it embraced the invading Arab armies with open arms. This view is not widely accepted however. Some authors have for example used mostly Arab sources to illustrate that "contrary to the claims of Muslim apologists, Iranians in fact fought long and hard against the invading Arabs." This view further more holds that once politically conquered, the Persians began engaging in a culture war of resistance and succeeded in forcing their own ways on the Arabs.

Persia Before the Conquest
Since the 1st century BC, the border between the Roman (later Byzantine) and Parthian (later Sassanid dynastic) empires had been the Euphrates river. The border was constantly contested. Most battles, and thus most fortifications, were concentrated in the hilly regions of the north, as the vast Arabian or Syrian Desert (Roman Arabia) separated the rival empires in the south. The only dangers expected from the south were occasional raids by nomadic Arab tribesmen. Both empires therefore allied themselves with small, semi-independent Arab principalities, which served as buffer states and protected Byzantium and Persia from Bedouin attacks. The Byzantine clients were the Ghassanids; the Persian clients were the Lakhmids. The Ghassanids and Lakhmids feuded constantly — which kept them occupied, but did not greatly affect the Byzantines or Persians. In the 6th and 7th centuries, various factors destroyed the balance of power that had held for so many centuries.

Revolt of the Arab Client States (602)
The Byzantine clients, the Arab Ghassanids, converted to the Monophysite form of Christianity, which was regarded as heretical by the established Byzantine Orthodox Church. The Byzantines attempted to suppress the heresy, alienating the Ghassanids and sparking rebellions on their desert frontiers. The Lakhmids also revolted against the Persian king Khusrau II. Nu'man III (son of Al-Monder IV), the first Christian Lakhmid king, was deposed and killed by Khusrau II in 602, because of his attempt to throw off the Persian tutelage. After Khusrau's assassination, the Persian Empire fractured and the Lakhmids were effectively semi-independent. It is now widely believed that annexation of Lakhmid kingdom was one of the main factors behind the Fall of Sassanid dynasty to the Muslim Arabs and the Islamic conquest of Persia, as the Lakhmids agreed to act as spies for the Muslims after being defeated in the Battle of Hira by Khalid ibn al-Walid.

Byzantine–Sassanid War (612 - 629)
See also: Fall of Sassanid dynasty

The Persian ruler Khusrau II (Parviz) defeated a dangerous rebellion within his own empire (the Bahram Chobin's rebellion). He afterwards turned his energies outwards, upon the traditional Byzantine enemies in the Roman-Persian Wars. For a few years, he succeeded gloriously. From 612 to 622, he extended the Persian borders almost to the same extent that they were under the Achaemenid dynasty(550–330 BC), capturing cities of Antioch, Damascus, Alexandria, and Jerusalem.

The Byzantines regrouped and pushed back in 622 under Heraclius. Khusrau was defeated at the Battle of Nineveh in 627, and the Byzantines recaptured all of Syria and penetrated far into the Persian provinces of Mesopotamia. In 629, Khusrau's son agreed to peace, and the border between the two empires was once again the same as it was in 602.

Assassination of Khusrau II
Khusrau II was assassinated in 628 and as a result, there were numerous claimants to the throne; from 628 to 632 there were ten kings and queens of Persia. The last, Yazdegerd III, was a grandson of Khusrau II and was said to be a mere child. However, no date of birth is known.

During Prophet Muhammad's Life
After the Treaty of Hudaybiyyah in 628, the Prophet Muhammad sent many letters to the princes, kings and chiefs of the various tribes and kingdoms of the time inviting them to convert to Islam. These letters were carried by ambassadors to Iran, Byzantium, Ethiopia, Egypt, Yemen, and Hira (Iraq) on the same day. This assertion has been cast into scrutiny by some modern historians of Islam--notably Grimme and Caetani. Particularly in dispute is the assertion that Khosrau II received a letter from Muhammad, as the Sassanid court ceremony was notoriously intricate, and it is unlikely that a letter from what at the time was a minor regional power would have reached the hands of the Shahanshah. With regards to Iran, Muslim histories further re-count that at the beginning of the seventh year of migration, Muhammad appointed one of his officers, Abdullah Huzafah Sahmi Qarashi, to carry his letter to Khosrau II inviting him to Islam:

"In the name of God, the Beneficent, the Merciful. From Muhammad, the Messenger of God, to the great Kisra of Iran. Peace be upon him, who seeks truth and expresses belief in God and in His Prophet and testifies that there is no god but God and that He has no partner, and who believes that Muhammad is His servant and Prophet. Under the Command of God, I invite you to Him. He has sent me for the guidance of all people so that I may warn them all of His wrath and may present the unbelievers with an ultimatum. Embrace Islam so that you may remain safe. And if you refuse to accept Islam, you will be responsible for the sins of the Magi."

There are differing accounts of the reaction of Khosrau II. Nearly all assert that he destroyed the letter in anger; the variations concentrate on the extent and detail of his response.

Rise of the Caliphate
The Islamic Prophet Mohammad died in June 632, and Abu Bakr was appointed Caliph and political successor at Medina. Soon after Abu Bakr's succession, several Arab tribes revolted against in the Ridda wars (Arabic for the Wars of Apostasy). The Campaign of the Apostasy was fought and completed during the eleventh year of the Hijri. The year 12 Hijri dawned, on March 18, 633, with Arabia united under the central authority of the Caliph at Medina. Whether Abu Bakr intended a full-out imperial conquest or not is hard to say; he did, however, set in motion a historical trajectory that in just a few short decades would lead to one of the largest empires in history, beginning with confrontation with Persian Empire under the general Khalid ibn al-Walid.

First conquest of Iraq (633)


After the Ridda Wars, a tribal chief of north eastern Arabia, Misnah ibn Haris, raided the Persian towns in Iraq. With the success of the raids, a considerable amount of booty was collected. Misnah ibn Haris went to Medina to inform Caliph Abu Bakr about his success and was appointed commander of his people, after which he begun to raid deeper into Iraq. Using the mobility of his light cavalry he could easy raid any town near the desert and within moments could disappear again in to the desert, into which the Sassanid army was unable to chase them. Misnah’s acts made Abu Bakr think about the expansion of the Rashidun Empire.

Abu Bakr started with the invasion of Iraq. The problems faced by Abu Bakr were that the Arabs feared the Persians with a deep, unreasoning fear which ran in the tribal consciousness as a racial complex and was the result of centuries of Persian power and glory. In return the Persian regarded the Arab with contempt. It was important not to suffer a defeat, for that would confirm and strengthen this instinctive fear. To make certain of victory, Abu Bakr decided on two measures; that the invading army would consist entirely of volunteers; and he put in command of the army his best general Khalid ibn al-Walid. After defeating the self-proclaimed prophet Musaylimah in the Battle of Yamama, Khalid was still at Al-Yamama when Abu Bakr sent him orders to invade the Sassanid Empire. Making Al-Hirah the objective of Khalid, Abu Bakr sent reinforcements and ordered the tribal chiefs of north eastern Arabia, Misnah ibn Haris, Mazhur bin Adi, Harmala and Sulma to operate under the command of Khalid along with there men. In about third week of March 633 (first week of Muharram 12th Hijrah) Khalid set out from Al-Yamama with an army of 10,000. The tribal chiefs, with 2,000 warriors each, joined Khalid; Thus Khalid entered the Persian Empire with 18,000 troops. After entering Iraq with his army of 18,000, Khalid won decisive victories in four consecutive battles: Battle of Chains, fought in April 633 A.D; Battle of River, fought in the 3rd week of April 633 A.D; Battle of Walaja, fought in May 633 A.D (where he successfully used a double envelopment manoeuvre), and Battle of Ullais, fought in the mid of May, 633 A.D. By now the Persian court already disturbed by the internal problems, was down and out. In the last week of May 633 A.D, Hira capital city of Iraq fell to the Muslims after resistance in the Siege of Hira. After resting his armies, in June 633 A.D Khalid laid siege of Al Anbar, which resisted and was eventually surrendered after a siege of a few weeks in July 633 A.D after the Siege of Al-Anbar. Khalid then moved towards the south, and conquered the city of Ein ul Tamr after the Battle of Ein ut Tamr in the last week of July, 633 A.D. By now, almost the whole of Iraq (Euphrates region) was under Islamic control. Khalid got a call of help from northern Arabia at Daumat-ul-Jandal, where another Muslim Arab general, Ayaz bin Ghanam, was trapped among the rebel tribes. Khalid went to Daumat-ul-jandal and defeated the rebels in the Battle of Daumat-ul-jandal in the last week of August, 633 A.D. Returning from Arabia, he got news of the assembling of a large Persian army. He decided to defeat them all separately to avoid the risk of defeat to a large unified Persian army. Four divisions of Persian and Christian Arab auxiliaries were present at Hanafiz, Zumiel, Sanni and Muzieh. Khalid devised a brilliant plan to destroy the Persian forces. He divided his army in three units, and attacked the Persian forces in brilliantly coordinated attacks from three different sides at night, starting from the Battle of Muzieh, then the Battle of Sanni, and finally the Battle of Zumail during November 633 A.D. These devastating defeats ended Persian control over Iraq, and left the Persian capital Ctesiphon unguarded and vulnerable for Muslims attack, before attacking the Persian Capital Khalid decided to eliminate all Persian forces from south and west, he accordingly marched against the border city of Firaz, where he defeated the combined forces of the Sassanid Persians, Byzantine Romans and Christian Arabs in the Battle of Firaz in December 633 A.D. This was the last battle in his conquest of Iraq. While Khalid was on his way to attack Qadissiyah, a key fort in the way to Persian Capital Ctesiphon, he received the letter of Caliph Abu Bakr and was sent to Roman front in Syria to assume the command of Muslim armies to conquer Roman Syria.

Second invasion of Iraq (636)
According to will of Abu Bakr, Umar was to continue the conquest of Syria and Iraq. On north eastern borders of Empire, in Iraq the situations were deteriorating day by day. During Abu Bakr’s Era Khalid ibn al-Walid who conquered Iraq was sent to Syrian front to command the Islamic armies there, as soon as Khalid left Iraq with his half army of 9000 soldiers Persians decided to take back there lost territory. Muslim army there in Iraq was forced to leave the conquered areas and concentrate on the border areas. Umar immediately sent reinforcement to aid Misna ibn Haris in Iraq under the command of Abu Ubaid al Saqafi. Persian forces defeated Abu Ubaid in the Battle of Bridge, however later Persian forces was defeated by Misnah bin harisah in the Battle of Baiyoub. In 635 Yazdgerd III sought alliance with Emperor Heraclius of Eastern Roman Empire. Heraclius married his daughter (according to traditions, his grand daughter) to Yazdegerd III, an old Roman tradition to show once allaince. While Heraclius prepared for a major offense in Levant, meanwhile Yazdegerd ordered concentration of massive armies to pull back Muslims from Iraq for good, this was suppose to be a well coordinated attacks by both emperors, Heraclius in Levant and Yazdegerd in Iraq, to annihilate the power of their common enemy Caliph Umar.Fate, however had decided otherwise.

Battle of Qadisiyyah
Umar ordered his army to retreat to the bordering areas of Iraq near Arabian desert and started raising armies to for the Persian campaign. Iraq was to be conquer once again from the beginning. Armies were concentrated near Madinah and owning to critical situation Umar decided to command the army in person. The idea was discouraged by the members of Majlis al Shura at Madinah. Muslims were engaged on both fronts and Umar's presence in Madinah was necessary, and only this way he could handle the critical situation. Umar appointed Saad ibn Abi Waqqas as commander for campaign in Iraq who left Madinah with his army in May 636 and camped at Qadisiyyah in June. While Heraclius launched his offense in May 636, Yazdegerd, probably owning to exhausted conditions of his government, could not coordinate with Heraclius in that offense and a would be decisive plan missed the mark. Umar having alleged intelligence of this alliance, devised his own genius plan. As battle was imminent with Byzantines in Syria, and Umar did not wanted to risk a decisive battle at a time with two great power, as in case of defeat on either front, Muslim empire could be paralyzed, which had already employed all of its available men power for this crucial moment of history. He wanted to finish off business first with Byzantines and thus reinforced Muslim army at Yarmouk sending 6000 soldiers as a reinforcement in small bands, thus giving impression of a continuous stream of reinforcement. Meanwhile Umar engaged Yazdegerd III in deception tactics, ordering Saad to enter in peace negotiations with Yazdegerd III apprantly inviting him to Islam. Heraclius had instructed his general Vahan, about not to engage in battle with Muslims until he orders. But fearing more reinforcement for Muslims from Madinah and their growing strength, Byzantines were left with no choice but to attack the Muslim forces before they get more stronger. Heraclius's imperial army was annihilated at Battle of Yarmouk in August 636 three months before Qadisiyyah, ending the power of the Roman Emperor for good. Yazdegerd III nevertheless continued to execute his offensive plan and concentrated armies near his capital Ctesiphon. . With situations at ease at Syrian front, on Umar's instruction negotiations were halt as an open signal to Persians for Battle. Saad defeated the powerful Persian army in the Battle of al-Qādisiyyah fought in 636 A.D the battle proved to be a key to Iraq. It marked the end of Sassanid rule west of Persia proper. The battle is regarded as one of the most decisive battle of Islamic and world history. The battle also achieved the achieved death of the famed Persian general Rostam Farrokhzād.Later Saad conquered Babylon, Koosie, Bahrahsher and Madein and the capital city of Persian Empire Ctesiphon fell in March 637 after a siege of three months.

Conquest of Iraq (636 - 638)
After the conquest of Ctesiphon, several detachments were immediately sent to west to capture Qarqeesia and Heet the forts at the border of Byzantine empire. Still several strong Persian armies were still active in north-east of Ctesiphon at Jalula and north of Tigris at Tikrit and Mosul. The greatest threat of all was the Persian concentration at Jalula. After withdrawal from Ctesiphon, the Persian armies gathered at Jalaula north-east of Ctesiphon. Jalaula was a place of strategically importance from where routes led to Iraq, Khurasan and Azerbaijan. The Persian forces at Jalaula were commanded by General Mihran. His deputy was General Khurrazad a brother of General Rustam, who commanded Persian forced at Battle of Qadisiyyah. As instructed by the Caliph Umar, Saad reported all the matter to Umar. Caliph decided to deal with Jalula first, his plan was first to clear the way to north before any decisive action against Tikrit and Mosul. Umar appointed Hashim ibn Uthba to the expedition of Jalula, and Abdullah ibn Mutaam to conquer Tikrit and Mosul. Some time in April 637 A.D., Hashim marched at the head of 12,000 troops from Ctesiphon and defeated Persians at Battle of Jalula, and laid siege of Jalula which lasted for seven months. The situation in north was not less tense, the Persian governor of Mosul marched to Tikrit and which lay north-west of Jalaula, and the strategy Persians was that the contingents from Tikrit could be sent to the help of the Persian army at Jalaula. It was also believed that in the event of Persian defeat at Jalaula, the Persians could take a stand at Tikrit. After victory at Jalula, as per the instructions of umar, Abdullah ibn Mutaam marched against Tikrit and captured the city after fierce resistance with the help of Christian Arabs he next sent detachment to Mosul which surrendered on the usual terms of Jizya. With victory at Jalula, and occupation of Takreet-Mosul region, Muslim rule in Iraq became unchallengeable.

After the conquest of Jalaula, a Muslim force under Qa'qa marched in pursuit of the Persians. The Persian army that escaped from Jalaula took its position at Khaniqeen fifteen miles from Jalaula on the road to Iran, under the command of General Mihran. Qa’qa defeated the Persian forces at Battle of Khaniqeen and captured the city of Khaniqeen. Persians withdrew to Hulwan. Qaqa moved to Hulwan and laid siege to the city which was captured in January 638. Qa’qa sought permission for operating deeper into Persian land, the main land Iran, but Caliph Umar didn’t approved the proposal and wrote a historic letter to Saad saying: "I wish that between the Suwad and the Persian hills there were walls which would prevent them from getting to us, and prevent us from getting to them. The fertile Suwad is sufficient for us; and I prefer the safety of the Muslims to the spoils of war."

Raids of Persians in Iraq (638 - 641)
By February 638 there was a lull in fighting on the Persian front. The Suwad, the Tigris valley, and the Euphrates valley were now under the complete control of the Muslims. The Persians had withdrawn to Persia proper, east of Zagros mountains. Persians kept on raiding Iraq, which remained political unstable. Nevertheless it appeared as if this was going to be the dividing line between the Rashidun Caliphate and the Sassanid Persians. In later part of the year 638 Hormuzan, who commanded one of the Persian corps at Battle of Qadisiyyah and was one of the seven great chiefs of Persia, intensified his raids in Iraq, Saad according to Umar’s instructions took offensive against Hormuzan and Utbah ibn Ghazwan aided by Nouman ibn Muqarin attacked Ahwaz and forced Hormuzan to enter into a peace treaty with Muslims according to which Ahwaz will remain Hormuzan’s estate and he will rule it as a vassal of Muslims and will pay tritube. Hormuzan broke the treaty and revolted against the Muslims, Umar sent Abu Musa Ashaari, governor of Busra to deal with Hormuzan. Hormuzan was defeated and sought once again for peace, Umar accepted the offer and Hormuzan was again made vassal of Muslims. This peace also proved short termed and once Hormuzan was reinforced by the fresh Persian troops sent by Emperor Yazdgerd III in late 640. The troops concentrated at Tuster north of Ahwaz, Umar sent Governor of Kufa, Ammar ibn Yasir, governor of Busra Abu Musa, and Nouman ibn Muqarin towards Tustar where Hormuzan was defeated, captured and sent to Madinah to Caliph Umar, where he apparently converted to Islam. He remained a useful adviser of Umar through out the campaign of conquest of Persia. He is also considered to be master mind behind the assassination of Caliph Umar in 644. After victory at Tustar, Abu Musa marched against Susa, a place of military importance, in January 641, which was captured after a siege of couple of months. Next Abu Musa marched against Junde Sabur, the only place left of military importance in the Persian province of Khuzistan which surrender to Muslims after the siege of few weeks.

Battle of Nihawand (641)
After the conquest of Khuzistan, the Caliph Umar wanted peace. They wanted to leave rest of Persia to the Persians. Umar said: "I wish there were a mountain of fire between us and the Persians, so that neither could they get to us, nor we to them. " But the Persians thought differently. The pride of the imperial Persians had been hurt by the conquest of their land by the Arabs. They could not acquiesce in the occupation of their lands by the Arabs.

After defeat of Persian forces at Battle of Jalula in 637, Emperor Yazdgerd III went to Rayy and from their moved to Merv and set up his capital there. From Merv he directed his chiefs to conduct continues raids in Iraq to destabilize the Muslim rule. With in next four years Yazdgerd III felt powerful enough to challenge Muslims once again for the throne of Iraq. The Emperor sent a call to his people to rise to a man to drive away the Muslims from their lands. In response to the call, hardened veterans and young volunteers from all parts of Persia marched in large numbers to join the imperial standard and marched to Nihawand for the last titanic struggle for the between the forces of Caliphate and Sassanid Persia. The forces assembled were about 60,000 and there commander was Mardan Shah. Governor of Kufa, Ammar ibn Yasir, got the intelligence of the Persian movements and concentration at Nihawand. He reported the matter to Umar. Before this event the policy of Umar had always remained non-offensive, he often wished that there may be a wall of fire between Muslims and Persians so that Muslims can’t cross into Persia not Persians could cross in Iraq. He for instance wished Iraq to be his eastern most frontiers, therefore he made peace with Hormuzan even after he broke the peace twice before. But with the concentration of Persian army at Nihawand. It was clear that until the Persia proper, will remain under the Sassanid control and the Emperor will keep on ruling Persia, he will not sit back but rather keep on raiding Iraq and might be in future Persians may get any break threw and might re-capture Iraq. This was more then enough for Umar, after years of non-offensive policy, now Caliph Umar was on war path. Hudheifa ibn Al Yaman was appointed commander of the forces of Kufa, and was ordered to march to Nihawand. Governor of Busra Abu Musa, was to march to Nihawand commanding his forces of Busra Nouman ibn Muqarrin marched from Ctesiphon to Nihawand while Umar decided to led the army concentrated at Madinah in person and command Muslims at the battle. Umar’s decision of commanding the army in person was not popularly accepted by the members of Majlis al Shura at Madinah. Though his presence would be a source of moral strength for the Muslim army but it was feared that if Muslims were defeated then it will be a great demoralization for Muslim troops. It was suggested that umar should command the campaign from Madinah, and would appoint an astute military commander to lead Muslim at Nihawand. Umar appointed Mugheera ibn Shuba, commander of the forces concentrated at Madinah and appointed Nouman ibn Muqarrin as commander in Chief of Muslims at Nihawand. All the Muslim corps left for Nihawand and first concentrated at Tazar, and then moved to Nihawand and defeated the Persian forces at Battle of Nihawand in December 641. Nouman died in action, and as per Umar’s instructions Hudheifa ibn Al Yaman became new commander in chief. After victory at Nihawand, Muslims captured the whole district of Hamadan after fable resistance by Persians.

Conquest of Persian Empire (642 - 644)
After years of non-offensive policy Umar now adopted a new offensive policy. The whole scale invasion of Sassanid Persian Empire was to begin. Battle of Nihawand, one of the most decisive battle in Islamic history and certainly the most decisive battle in the history of Persian empire, more decisive then Alexander’s fatal blow at Battle of Gaugamela, in terms that after Gaugamela, Persians recovered with in few decades and built an other Persian empire, but after Umar blow to Persians at Nihawind, Persians would never raise an other empire. The battle proved to be a key to Persia. After a devastating defeat at Nihawand, last Sassanid Persian Emperor Yazdgerd III, a man with iron nerves, was never to be able again to raise more troops to resist the mighty onslaught of Umar, it had now became a war between two rulers, Umar will follow Yazdgerd III to every corner of his empire either will kill him or will capture him, like he did with Hormuzan. Yazdgerd III would have a narrow escape at Marv when Umar’s lieutenant was to capture him, he would save his life only by fleeing to China, far enough from reach of Umar, thus effectively ending the 400 years old Sassanid dynasty. The conquest of Sassanid Persian Empire, by commanding the operations, sitting about 1000 kilometer away from the battle fields, will become the greatest triumph of Umar and his strategic marvel, and marked his reputation as one of the greatest military and political genius of all time, like his late cousin Khalid ibn Walid (590 – 642).

Strategic planning for the conquest of Persian Empire
Umar decided to strike Persians immediately after their defeat at Nihawand to have psychological advantage on them. The main strategic problem before Umar was from where to start the offensive. There were three alternatives, Fars in south, Azerbaijan in north or Isfahan in center. Umar closed Isfahan to be the first target. His strategy was to strike heart of Persian Empire this will cut off supply line and communication of Sassanid garrisons from of rest of Persian provinces, thus will isolate Fars, Azerbaijan, from Khurasan. The next attacks will launched against Fars, after capturing the heart land of Persia, that is Fars and Isfahan simultaneously attacks will be launched against Azerbaijan, the north western province and Sistan, the eastern most province of Persian Empire. Conquest of these provinces will leave Khurasan, the stronghold of Emperor Yazdegerd III isolated and vulnerable. In the last phase of this grand campaign Khurasan was to be attacked. This will be a last nail in the coffin of Sassanid dynasty. The plan was formulated and preparations were completed by January 642. The success of plan depended upon how brilliantly Umar will co-ordinate these attacks from Madinah, about 1000 miles from the battle fields in Persia and upon skills and abilities of his field commanders. Umar would appoint his best field commanders to conquer the Sassanid Persian Empire and bring down his most formidable foe Emperor Yazdegerd III. The campaign saw a different pattern in command structure. Umar will not appoint a single field commander to campaign across the Persian lands, he would rather appoint several commanders each with his own objectives, and once the mission was over he will be acting as an ordinary sub-ordinate under the new field commander for the next mission. This was done by Umar to prevent any of his commanders to gain prominence and power that would in future, threaten his own authority, as in 638 he feared Khalid’s growing power and popularity and dismissed him from military services when he was at zenith of his military career, though at his dismissal, Khalid was more then able to rebel against Umar but never rebelled and made a soft corner in Umar’s heart. In 642 at the eve of conquest of Persia, Umar in order to give a moral boost to his troops decided to reinstall Khalid as new field commander against Persia. Already well reputed as invincible military commander and conqueror of eastern provinces of Roman, Khalid’s presence in Persia would strike terror in Persian commanders, most of whom had already faced Khalid in 633 during his lightning conquest of Iraq. Umar wanted a sure victory in early campaigns, which would increase confidence of his troops and meanwhile demoralize Persians. Unfortunately before Umar could issue orders of re-appointment, Khalid, residing in Emesa, died. In various campaigns of Persia, Umar even himself appointed the commanders of wings, center and cavalry of the army. Umar strictly instructed his commanders to consult him before making any decisive move in Persia. All the commanders, before starting their assigned campaigns were instructed to send a detail report of the geography and terrain of the region and position of Persian garrisons, forts, cities and troops in it. Then Umar will sent them a detail plan of how he want this region to be capture, only the tactical issues were left to the field commander to be tackled in accordance with the situation they are facing at their front. Umar appointed the best available and well reputed commanders for the campaign.

Conquest of central Persia (Isfahan & Tabaristan)
The preparation and planning of conquest of Persian Empire was completed by early 642. Umar appointed Abdullah ibn Uthban, commander of Muslim forces to invade Isfahan. From Nihawand Abdullah marched to Hamadan, which was already in Muslim hand. From Hamadan, Abdullah marched to North East to Rayy, about 200 miles from Hamadan and laid siege to the city which surrendered after fierce resistance. Once Rayy was captured Abdullah marched 230 miles south east against Isfahan city and laid siege to it, here Muslim army was reinforced by the fresh troops from Busra and Kufa under the command of Abu Musa Ashaari and Ahnaf ibn Qais. The siege continued for few months and finally city surrendered. From Isfahan Abdullah again marched 150 miles north-east towards Qom, which was captured with out much resistance. This was the outer most boundary of Isfahan region. Further north east of it laid Khurasan, and south east of it lay Sistan. Meanwhile Hamadan and Rayy had rebelled, Umar sent Naiem ibn Muqarrin, brother of late Nauman ibn Muqarrin, who was Muslim commander at Nihawand, to crush the rebellion and clear the western most boundaries of Isfahan. Naiem marched towards Hamadan from Isfahan, a bloody battle was fought and Hamadan was recaptured by Muslims, Naiem next moved to Rayy, here too Persians resisted and were defeated out side the fort, and city was recaptured by muslims. Persian citizen sought for peace and agreed to pay Jizya. From Rayy, Naiem moved north towards Tabaristan, which laied south of Caspain Sea. The ruler of Tabaristan surrendered and a peace treaty was signed according to which he will govern Tabaristan on behalf of Caliph and will pay annual Jizya. This was all done in April 642. Naiem’s brother advanced further north and captured Qumas, Jarjan and Amol. He too signed a peace treaty with locals according to which they will accept the Muslim rule over area and will pay Jizya. With this campaign that ended some time 643, Muslims were master of Tabaristan. Further North West of the region laid Azerbaijan.

Conquest of southern Persia (Fars)
With Isfahan firmly in Muslim hand, conquest of Fars begun about the same time when conquest of Tabaristan was started. The first army that will penetrate Fars, was under the command of Maja’a ibn Masood, his objective was Sabur. Maja’a marched from Busra to Tawwaj, where Persian forces halt his way and were defeated in a quick battle thus fought. From Tawwaj Maja’a moved to Sabur, which was a fortified town. The siege continued for few weeks after which city surrendered and usual terms of Jizya were enforced on it. With the conquest of Sabur Maja’a ibn Masood’s mission was over. Reinforcement came under the command of Usman ibn Abi al-Aas, who took over the command of Majaa’s army. Usman’s objective was ancient Persian capital city of Persepolis. Usman marched from Tawwaj to Shiraz, which surrendered peacefully. From Shiraz, Usman moved 35 miles north to Persepolis and laid siege to the historic Persian city. Siege lasted for several weeks before the city surrendered. Usman’s mission was over at Persepolis. Here again a change of command occurred. The mission to captured eastern districts of Fasa and Darab was given to Sariyah ibn Zuneim, who moved 80 miles south east to capture Fasa and then Darab, 60 miles from Fasa after resistance from local Persian garrisons. With this last successful expedition, conquest of Fars was completed by late 642. Further east of Fars laid Kerman and Sistan. A simultaneous campaign was launched against eastern (sistan and Balochistan), southern (Kerman and Makran) and north western (Azerbaijan) Persia.

Conquest of south eastern Persia (Kerman & Makran)
Expedition to Kerman was sent roughly at the same time when expedition to Sistan and Azerbaijan were sent. Suhail ibn adi was given command of this expedition. Suhail marched from Busra in 643, passing from Shiraz and Persepolis he join with other Muslim armies and marched against Kerman, which was subdued after a pitch battle with local garrisons. Further east of Kerman laid Makran what is now a part of present day Pakistan. It was domain of Hindu king of Rasil (sindh), who acted as a vassal of Sassanid Persians. Raja of Rasil concentrated huge armies from Sindh and Balochistan to halt the advance of Muslims. Suhail was reinforced by Usman ibn Abi Al Aas from Persepolis, and Hakam ibn Amr from Busra, the combined forces defeated Raja Rasil at Battle of Rasil, who retreated to the eastern bank of River Indus. Further east from Indus River laid Sindh. Umar, after knowing that sindh was a poor and relatively barran land, disapproved Suhail’s proposal to cross Indus River. For the time being, Umar declared the Indus River, a natural barrier, to be the eastern most frontier of his domain. This campaign came to an end in mid 644.

Conquest of eastern Persia (Sistan)
Sistan was belived to be the largest province of Sassanid Empire. In south it bordered with Kerman and in North with Khurasan. It stretches from what is now Balochistan, Pakistan in east and southern Afghanistan in north. Asim ibn Amr, veteran of great battles of Qadisiyyah and Nihawand was appointed to conquer Sistan. Asim marched from Busra, and passing through Fars and taking under his command the Muslim troops already present in fars entered Sistan. No resistance was offered and cities surrendered. Asim reached Zaranj, 250 miles from Kandahar, a small town in present day southern Afghanistan, then a bustling capital of Sistan. Asim laid siege to the city which lasted several months. A pitch battle was fought out side the city and Persians were defeated and routed. With the surrender of Zaranj, Sistan submitted to Muslim rule. Further east of sistan was northern Sindh which was beyond the scope of the mission assigned to Asim. Caliph for the time bring, didn’t approved of any incursion in the land east of Persian Empire and ordered his men to consolidate power in newly conquered land.

Conquest of Azerbaijan
Conquest of Azerbaijan started in 643. It was part of simultaneous attack launched against north, south and east of Persia, after capturing Isfahan and Fars. These brilliantly coordinated multi-prong attacks by Caliph Umar, paralyzed whole of what then remained of Persian Empire. Expeditions were sent against Kerman and Makran in south east, against Sistan in north east and against Azerbaijan in North West. Hudheifa ibn Al Yaman was appointed commander to conquer Azerbaijan. Hudheifa marched from Rayy in central Persia to Zanjan, a stronghold of Persians in north. Zanjan was a well defended fortified town, Persians came out of the city and gave a battle, Hudheifa defeated the Persian garrison and captured the city, as per Caliph Umar’s order, the civilians who sought for peace were given peace on the usual terms of Jizya. From Zanjan, Hudheifa marched to Ardabil which surrendered peacefully and Hudheifa continued his march north along with the western coast of Caspian Sea and captured Bab by force. At this point Hudheifa was recalled by Caliph umar. Bukair ibn Abdullah and Utba ibn Farqad succeeded him. They were sent to carry out a two prong attack against Azerbaijan. Bukair was to march north along western coast of Caspian Sea while Uthba will march direct in the heart of Azerbaijan. On his way north Bukair was halt by a large Persian force under Isandir. A pitch battle was fought and Isandir was defeated and captured. Isandir in return of safety of his life agreed to surrender his estates in Azerbaijan and persuade others for submission to the Muslim rule. Uthba ibn Farqad defeated Bahram, brother of Isandir. He too sought for peace. A pact was drawn according to which Azerbaijan was surrendered to Caliph Umar on usual terms of paying annual Jizya. The espedition commenced some time in late 643.

Conquest of Armenia
Byzantine Armenia was already conquered in 638-639. Persian Armenia lay north of Azerbaijan. By now except for Khurasan and Armenia, whole of Persian Empire was under Umar’s control and Emperor Yazdegred III was on run. Umar never wanted to take a chance, he never perceived Persian as weak and weary. In Umar’s this sense of perception laid his secret of brilliant and speedy conquest of Persian Empire. This time again Umar decided to send simultaneous expeditions to far north east and north west of Persian Empire. An expedition was sent to Khurasan in late 643 and at the same time an expedition was launched against Armenia. Bukair ibn Abdullah, who had recently subdued Azerbaijan, assigned mission to Capture Tiflis, present day capital of Georgia, then a Capital of Persian Armenia. From Bab at western coast of Caspian Sea, Bukair continued his march north. Umar decided to practice his traditional and successful strategy of multi-prong attacks. While Bukair was still miles away from Tiflis, Umar instructed him to divide his army into three corps. Umar appointed Habib ibn Muslaima to capture Tiflis, Abdulrehman to march north against the mountains and Hudheifa to march against southern mountains. Habib captured Tiflis and region up to eastern coast of Black Sea. Abdulrehman marched north to Caucasus mountain and subdued the tribes. Hudheifa marched south west to the mountainous region and subdued the local tribes. The advance in Armenia came to an end with the death of Caliph umar in November 644. By then almost whole of Caucasus was captured.

Conquest of Khurasan
Khurasan was second largest province of Sassanid Persian Empire. It stretches from what is present day north eastern Iran, Afghanistan and Turkmenistan. Its capital was Balkh, now in present day northern Afghanistan. The mission of conquering Khurasan was assigned to Ahnaf ibn Qais. Ahnaf marched from Kufa and took a short and less frequent route via Rayy and Nishapur. Rayy was already in Muslim hand and Nishapur surrendered with out resistance. From Nishapur Ahnaf marched to Herat which in now in present day southern Afghanistan. Herat was a fortified town, Siege of Herat lasted for few months before Herat surrendered. With the surrender of Heart, whole of the southern Khurasan came under Muslim control. With Herat under his firm control, Ahnaf marched north direct to Merv, in present Turkmenistan. Merv was the capital of Khurasan and here Yazdegred III held his court. On hearing of the Muslim advance, Yazdegred III left for Balkh. No resistance was offered at Merv, and the Muslims occupied the capital of Khurasan without firing a shot. Ahnaf stayed at Merv and waited for reinforcement from Kufa. Meanwhile Yazdgird had also gathered considerable power at Balkh and also sought alliance with the Khan of Farghana, who personally led the Turkish contingent to help Yazdegred III. Umar ordered that Yazdgird’s allied forces should be weaken by breaking up the alliance with Turks. Ahnaf successfully break up the alliance and Khan of Farghana pulled back his forces realizing that fighting with Muslims is not a good idea and it might endanger his own kingdom. Yazdgird's army was defeated at Battle of Oxus River and retreated across the Oxus to Transoxiana. Yazdegred III had a narrow escape and fled to China. Balkh was occupied by the Muslims, and with this occupation the Persian war was over. The Muslims had now reached the outermost frontiers of Persia. Beyond that lay the lands of the Turks and still further lay China. The old mighty empire of the Sassanids had ceased to exist. Ahnaf returned to to Marv and sent a detail report of operations to Umar and a historic letter that Umar was anxiously waiting for, subject of which was that Persian Empire has been conquered and a permission was sought whether Oxus should be crossed to invade Transoxiana or not. Umar ordered Ahnaf to consolidate his power south of Oxus.

Persian rebellion
Caliph Umar was assassinated in November 644, by a Persian Slave. The assassination is often seen by various historians as a Persian conspiracy against Umar. Hormuzan is said to have master minded this plot. Caliph Uthman ibn Affan (644-656) succeeded Umar. During his reign almost whole of the former Sassanid empire's territory rebeled time to time until 651, when the last Sassanid emperor was assasinated near Merv ending Sassanid Dynasty and Persian resistance to Muslims. Caliph Uthman thus directed several military expeditions to crush rebillion and re-capture the Persia and their vassal states. The Empire expanded beyond the borders of Sassanid Empire in Transoxiana, Baluchistan and Caucasus. The main rebellion was in the Persian provinces of Armenia, Azerbaijan, Fars, Sistan ( in 649), Tabaristan, Khorasan (651), and Makran (650).

End of the Sassanid Dynasty
Yazdegerd III after being defeated at Battle of Oxus river was unable to raise another army and became a hunted fugitive. Following the battle he fled to central asia at the court of Khan of Farghana. From there Yazdegerd went to China. Nevertheless Yazdegerd III keep on intruding in Persia, using his influence over the notables and chiefs of Persia, thus remained a motivating force behind the Persian rebellion. During Caliph Uthman's reign Yadegerd III came back to Bactria and Khurasan rebelled against Caliphate. Abdullah ibn Aamir crushed the rebellion and defeated Yazdegerd's forces. He fled from one district to another until a local miller killed him for his purse at Merv in 651. For many decades to come, this was the easternmost limit of complete Muslim rule.

Persia under Muslim rule
Under Umar and his immediate successors, the Arab conquerors attempted to maintain their political and cultural cohesion despite the attractions of the civilizations they had conquered. The Arabs initially settle in the garrison towns rather than on scattered estates. The new non-Muslim subjects, or dhimmi, were to pay a special tax, the jizya or poll tax, which was calculated per individual at varying rates, usually two dirhams for able bodied men of military age, in return for their exemption from military services. Women and Children were exempted from Jizya. . Mass conversions were neither desired nor allowed, at least in the first few centuries of Arab rule. The Islamic prophet Muhammad had made it clear that the "People of the Book", Jews and Christians, were to be tolerated so long as they submitted to Muslim rule. Sassanid state religion was Zoroastrianism and its worshipers were declared people of the book, and were entitled to the same tolerance. While Persian sources claim destruction of Zoroastrian shrines and prohibition of Zoroastrian worship, Muslim sources didn't mentioned of any such incident with the people who accepted their rule peacefully. The Zoroastrian temples, were converted to Mosques and often were destroyed in the cities which fall to Muslims after relentless resistance. Cities that submitted to Muslim rule through peace negotiation with Muslims prior, during or after the siege or conquest, were given peace on liberal terms as per Caliph Umar's instructions, allowing the inhabitants to practice any religion they wish and their holy sites were given protected until they pay Jizya annually.

Umar, knew the fact that his grip over Persians will never be firm until he conquers their trust. Therefore according to his instruction citizens were given peace, whether the city fall by force or through peaceful negotiation. Only Jizya, which was an average 2 dirham per adult man, was imposed on them, which was far lower then the taxes imposed by Sassanid rulers on peasant class during last troubled years of their rule, thus Jizya simply replaced those, often unbearable, taxes. During Rashidun Caliphate, the official language of Persia remained Persian. The Diwan of Persians were written in Persian language, similarly the official languages of Syria and Egypt remained Greek and Coptic. However, During the Ummayad Caliphate, the Ummayads imposed Arabic as the primary language of the subject peoples throughout their empire, displacing their indigenous languages. However, Middle Persian proved to be much more enduring. Most of the structure and vocabulary survived, evolving into the modern Persian language. However, Persian did incorporate a certain amount of Arabic vocabulary, especially as pertains to religion, as well as switching from the Pahlavi Aramaic alphabet to a modified version of the Arabic alphabet. Before the conquest, the Persians had been mainly Zoroastrian; there were also large and thriving Christian and Jewish communities, along with smaller numbers of Buddhists and other groups. However, there was a slow but steady movement of the population toward Islam. The nobility and city-dwellers were the first to convert, Islam spread more slowly among the peasantry and the dihqans, or landed gentry. By the late 10th century, the majority of Persians had become Muslim, at least nominally. Most Persian Muslims were Sunni Muslims. Though Iran is known today as a stronghold of the Shi'a Muslim faith, it did not become so until much later around the 15th century. The Iranian Muslims projected many of their own Persian moral and ethical values that predates Islam into the religion, while recognizing Islam as their religion and the prophet's son in law, Ali as an enduring symbol of justice.

According to Bernard Lewis: "'Arab Muslims conquests have been variously seen in Iran: by some as a blessing, the advent of the true faith, the end of the age of ignorance and heathenism; by others as a humiliating national defeat, the conquest and subjugation of the country by foreign invaders. Both perceptions are of course valid, depending on one's angle of vision… Iran was indeed Islamized, but it was not Arabized. Persians remained Persians. And after an interval of silence, Iran reemerged as a separate, different and distinctive element within Islam, eventually adding a new element even to Islam itself. Culturally, politically, and most remarkable of all even religiously, the Iranian contribution to this new Islamic civilization is of immense importance. The work of Iranians can be seen in every field of cultural endeavor, including Arabic poetry, to which poets of Iranian origin composing their poems in Arabic made a very significant contribution. In a sense, Iranian Islam is a second advent of Islam itself, a new Islam sometimes referred to as Islam-i Ajam. It was this Persian Islam, rather than the original Arab Islam, that was brought to new areas and new peoples: to the Turks, first in Central Asia and then in the Middle East in the country which came to be called Turkey, and of course to India. The Ottoman Turks brought a form of Iranian civilization to the walls of Vienna.'"

Literature

 * Bashear, Suliman — Arabs and Others in Early Islam, Darwin Press, 1997
 * Daniel, Elton — The History of Iran, Greenwood Press, 2001
 * Donner, Fred — The Early Islamic Conquests, Princeton, 1981
 * M. Ismail Marcinkowski, Persian Historiography and Geography: Bertold Spuler on Major Works Produced in Iran, the Caucasus, Central Asia, India and Early Ottoman Turkey, with a foreword by Professor Clifford Edmund Bosworth, member of the British Academy, Singapore: Pustaka Nasional, 2003, ISBN 9971-77-488-7.
 * Sicker, Martin — The Islamic World in Ascendancy: From the Arab Conquests to the Siege of Vienna, Praeger, 2000
 * Zarrin’kub, Abd al-Husayn — Ruzgaran : tarikh-i Iran az aghz ta saqut saltnat Pahlvi, Sukhan, 1999. ISBN 964-6961-11-8
 * Arab Conquest of Iran, pp. 203–10, Encyclopaedia Iranica.

الفتح الإسلامي لفارس Conquista musulmana de Persia fa:حمله اعراب به ایران Conquête musulmane de la Perse イスラーム教徒のペルシア征服 Den islamske erobringen av Iran İran'da İslam 伊斯兰对波斯的征服