Alids

The Alids are those who claim descent from Ali ibn Abi Talib (عَلِيّ بْن أَبِي طَالِب; c. 600–661 CE), the fourth Rashidun caliph ((r. 656 – 661)) and the first imam in Shia Islam. Ali was also the cousin and son-in-law of the Islamic prophet Muhammad. The main branches are the Hasanids and Husaynids, named after Hasan and Husayn, the eldest sons of Ali from his marriage to Fatima, the daughter of Muhammad. As the progeny of Muhammad, they are revered by all Muslims. The Alids have led various movements in Islam, and a line of twelve Alids are the imams in Twelver Shia, the largest Shia branch.

Children of Ali
In addition to seventeen daughters, various sources report that Ali had eleven or fourteen, or eighteen sons. His first marriage was to Fatima, daughter of the Islamic prophet Muhammad, who bore Ali three sons, namely, Hasan, Husayn, and Muhsin, though the last one is not mentioned in some sources. Muhsin either died in infancy, or was miscarried after Fatima was injured during a raid on her house to arrest Ali, who had withheld his pledge of allegiance from the first Rashidun caliph Abu Bakr ((r. 632 – 634)). The former report appears is Sunni sources and the latter in Shia sources. Hasan and Husayn are recognized as the second and the third Imams in Shia Islam, their descendants being known as the Hasanids and the Husaynids, respectively. They are revered by all Muslims as the progeny of Muhammad and honored by nobility titles such as Sharif and Sayyid. Ali and Fatima also had two daughters, namely, Zaynab and Umm Kulthum. After the death of Fatima in 632 CE, Ali remarried and had more children. Among them, the lineage of Ali continued through Muhammad ibn al-Hanafiya, Abbas ibn Ali, and Umar al-Atraf, their descendants were honored by the title Alawi (lit. 'of Ali'). Respectively, they were born to Khawla al-Hanafiyya, Umm al-Banin, and Umm Habib bint Rabi'a (al-Sahba).

Umayyads era ((r. 661 – 750))
Mu'awiya seized the rule after the assassination of Ali in 661 and founded the Umayyad Caliphate, during which the Alids and their supporters were heavily persecuted. After Ali, his followers (shi'a) recognized as their imam his eldest son Hasan. After his death in 670, they turned to his brother Husayn, but he and his small caravan were massacred by the Umayyads in the Battle of Karbala in 680. Soon followed the Shia uprising of al-Mukhtar in 685 on behalf of Muhammad ibn al-Hanafiya. Many more Shia revolts followed afterward, led not only by the Alids but also by other kinsmen of Muhammad.

The main movements in this period were the now-extinct Kaysanites and the Imamites. Named after a commander of al-Mukhtar, the Kaysanites energetically opposed the Umayyads and were led by various relatives of Muhammad. Their majority followed Abu Hashim, the son of Ibn al-Hanafiya. When Abu Hashim died around 716, this group followed Muhammad ibn Ali ibn Abd-Allah, the great-grandson of Muhammad's uncle Abbas ibn Abd al-Muttalib. The Kaysanite movement thus aligned itself with the Abbasids, that is, the descendants of Abbas ibn Abd al-Muttalib. On the other hand, the Imamites were led by the quiescent descendants of Husayn through his only surviving son, Ali Zayn al-Abidin, their fourth imam. His son Zayd ibn Ali was an exception for he led a failed uprising against the Umayyads around 740. The followers of Zayd went on to form the Zaydites, for whom any learned Hasanid or Husaynid who rose against tyranny was qualified as imam.

Abbasids era ((r. 750 – 1258))
To overthrow the Umayyads, the Abbasids had rallied the support of the Shia in the name of the Ahl al-Bayt, that is, the family of Muhammad. But many Shias were disillusioned when the Abbasid al-Saffah ((r. 750 – 754)) declared himself caliph, as they had hoped for an Alid leader instead. The Abbasids soon turned against their former allies and persecuted the Alids and their Shia supporters. In response, Shia doctrinally limited its leadership to the Alids, many of whom revolted against the Abbasids, including the Hasanid brothers Muhammad ibn Abd-Allah and Ibrahim. Some Alids instead took refuge in remote areas and founded regional dynasties in the southern shores of the Caspian sea, Yemen, and western Maghreb. For instance, the revolt of the Hasanid Husayn ibn Ali al-Abid was suppressed in 786 but his brother Idris escaped and founded the first Alid dynasty in Morocco. Similarly, a number of Zaydite rules appeared in northern Persia and in Yemen, the latter of which has survived to the present day.

Some quiescent imams of the Imamites were also probably killed by the Abbasids. For example, their seventh imam, Musa al-Kazim, spent years in the Abbasid prisons and died there, possibly poisoned by order of Caliph Harun al-Rashid ((r. 786 – 809)), who also had "hundreds of Alids" killed. Caliph al-Ma'mun ((r. 813 – 833)) later attempted a reconciliation by appointing in 816 as his heir Ali al-Rida, the eighth imam of the Imamites. But other Abbasids revolted in opposition in Iraq, which forced al-Ma'mun to reverse his policies and Ali al-Rida died around that time, likely poisoned. Ali al-Hadi and Hasan al-Askari, the tenth and eleventh imams of the Imamites, were held in the capital Samarra under strict surveillance. Most Imamite sources report that both were poisoned by the Abbasids. Their followers also believe that the birth of their twelfth imam, Muhammad al-Mahdi, was hidden for fear of Abbasid persecution and that he remains in occultation by divine will since 874, until his reappearance at the end of time to eradicate injustice and evil. They became known as the Twelvers.

Meanwhile, the only historic split among the Imamites happened after the death in 765 of their sixth imam, the quiescent Ja'far al-Sadiq, who played a key role in formulating Imamite doctrines. Some claimed that his designated successor was his son Isma'il, who had actually predeceased al-Sadiq. These followers permanently separated and later formed the Isma'ilites. Some of them denied the death of Isma'il but their majority accepted the imamate of his son Muhammad ibn Isma'il. His death around 795 was denied by the majority of his followers, who awaited his return as the Mahdi, while a minority traced the imamate in his descendants. The Isma'ilites actively opposed the Abbasids, and their efforts culminated in the establishment of the Fatimid Caliphate ((r. 909 – 1171)) in North Africa, although some have questioned the Isma'ilite ancestry of the Fatimid caliphs.

The abortive Zanj rebellion against the Abbasids was ignited in Iraq and Bahrain in the mid-ninth century by Ali ibn Muhammad Sahib al-Zanj, who claimed descent from Abbas ibn Ali. The poetry by descendants of Abbas ibn Ali is collected in al-Awraq, compiled by the Turkic scholar al-Suli. One of his descendants was Abbas ibn al-Hasan al-Alawi, who reached fame as a poet and scholar during the reigns of Harun al-Rashid and al-Ma'mun.

Alid dynasties
Several dynasties have claimed descent from Ali, often through his son Hasan. The Hasanid dynasties include the Idrisites and Sharifs of Maghreb in North Africa, and Hammudids in Andalusia, located in modern-day Spain. The Fatimid Caliphate claimed a Husaynid descent.