Ethiopian–Adal War

The Ethiopian–Adal War or Abyssinian–Adal War, also known in Arabic as Futūḥ Al-Ḥabaša (فتوح الحبش), was a military conflict between the Christian Ethiopian Empire and the Muslim Adal Sultanate from 1529 to 1543. The Christian Ethiopian troops consisted of the Amhara, Tigrayans, Tigrinya and Agaw people, and at the closing of the war, supported by the Portuguese Empire with no less than four hundred musketeers. The Adal forces were composed of Harla, Somali, Afar, as well as Arab and Turkish gunmen. Both sides would see the Maya mercenaries at times join their ranks.

Background
Imam Ahmad ibn Ibrahim al-Ghazi was a military leader of the medieval Adal Sultanate in the northern Horn of Africa. Between 1529 and 1543, he embarked on a campaign referred to as the Futuh Al-Habash, bringing the three-quarters of Christian Abyssinia under the control of the Muslim empire. With an army composed of Afar, Harari, and Somalis, al-Ghazi's forces came close to extinguishing the ancient Ethiopian kingdom. However, the Abyssinians managed to secure the assistance of Cristóvão da Gama's Portuguese troops and maintain their domain's autonomy. Both polities exhausted their resources and manpower in the process, resulting in the contraction of the two powers and altering regional dynamics for centuries to come. Many historians trace the origin of hostile Ethiopia–Somalia relations to this war. Some scholars also argue that this conflict proved the value, through their use on both sides, of firearms such as the matchlock musket, cannons, and the arquebus over traditional weapons.

Course of the war
In 1529, Imam Ahmad's Adal troops defeated a larger Ethiopian contingent at the Battle of Shimbra Kure. The Harari cavalry was instrumental in this battle, as the Abyssinian troops were outmaneuvered.

The victories that gave the followers of Imam Ahmad the upper hand came in 1531. The first was the Battle of Antukyah, where cannon fire at the start panicked the Ethiopian soldiers. The second was the Battle of Amba Sel, where troops under the Imam not only defeated but dispersed the Ethiopian army and captured items of the Imperial regalia. These victories allowed the Adalites to enter the Ethiopian highlands, where they began to sack and burn numerous churches, including Atronsa Maryam, where the remains of several Emperors had been interred.

He defeated the armies of Agame and Tembien and marched towards Aksum to capture the historical Ethiopian city to solidify his rule in Ethiopia, echoing Mehmed II conquest of Constantinople, but the locals of Tigray had all assembled to defend their holy city. The Imam defeated and killed a large number of them as Arab Faqīh states, "Not a single one managed to slip away. They killed them in the forts, in the valleys and in the gorges. The ground was so thickly covered with their corpses, that it was impossible to walk in that place because of the dead bodies." he estimates that over 10,000 Christians were killed. The Imam reached Aksum he besieged the city in the siege of Axum where upon he destroyed the Church of Our Lady Mary of Zion. During his invasion of the Tigray region Ahmad ibn Ibrahim al-Ghazi visited the tomb of Najashi in Negash to pay his respects.

Dawit II died in September 2nd, 1540. and his son and future emperor Prince Menas was captured by the forces of Imam Ahmad; the Empress was unable to react as she was besieged in the capital. The first Adalite encounter with Portuguese forces occurred in 1541, when the latter were marooned in Massawa following their defeat at the hands of the Ottomans at the 1541 Battle of Suez. The Portuguese forces would be ambushed by the Adalites at the Battle of Massawa in the same year. In 1543, a smaller number of Abyssinians soundly defeated the larger Adal-Ottoman army with the help of the Portuguese navy, which brought 400 musketeers led by Cristóvão da Gama via Massawa, a port in the province of Medri Bahri, an important port today in present-day Eritrea. However, Da Gama was captured in the Battle of Wofla and later killed.

The 500 musketeers were led by Bahri Negassi Yeshaq, king of Medri Bahri. Yeshaq provided the Portuguese with not only provisions and places to camp in his realm but also information about the land. The Bahri Negassi also joined Emperor Gelawdewos and the Portuguese in the decisive Battle of Wayna Daga, where tradition states that Imam Ahmad was shot in the chest by a Portuguese musketeer named João de Castilho, who had charged alone into the Muslim lines and died. The wounded Imam was then beheaded by an Ethiopian cavalry commander, Azmach Calite. Once the Imam's soldiers learned of his death, they fled the battlefield. The death of Imam Ahmad and the victory at Wayna Daga caused a collapse of Ahmad's forces and forced an Adalite retreat from Ethiopia.

Emir Nur ibn Mujahid succeeded his uncle Imam Ahmad as leader of the Adal forces and consolidated his power by marrying Bati del Wambara. In 1559, Emir Nur's cavalry defeated and killed Emperor Gelawdewos in battle, and sacked the Abyssinian town of Waj. Simultaneously, Abyssinian General Ras Hamalmal sacked the Adalite capital Harar, captured Sultan Barakat ibn Umar Din, and executed him, thus ending the Walashma Dynasty.

J. Spencer Trimingham postulates that the captured Sultan Barakat was in fact returned to Adal in exchange for Prince Menas in negotiations led by Bati del Wambara. Emir Nur ibn Mujahid, returning from his campaign, would display the head of Emperor Gelawdewos in Harar as a show of triumph. In 1577, Emperor Sarsa Dengel defeated, captured, and executed Sultan Muhammad V in Bale. He was succeeded by Imam Muhammad Gasa, a relative of Imam Ahmad, who relocated the capital of Adal to Aussa, while Susenyos I relocated the capital of Abyssinia to Gondar.

Aftermath
The war was devastating for the Harari people which resulted in massive casualties for them and the conflict is regarded as one of the reasons for their rapid population decline. Mohammed Hassen has plausibly argued that because this conflict severely weakened both participants, it provided an opportunity for the Oromo people to conquer and migrate into the historically Gafat land of Welega south of the Blue Nile and eastward to the walls of Harar, establishing new territories.