This article is about the African sultanate. For the Norse mythological figure, see Adal (mythology).

Adal was a sixteenth century sultanate located in East Africa north of Ethiopia, in modern Eritrea and Djibouti. At its height, the country controlled large portions of Ethiopia and Somalia.

A previous Islamic state in the region, the Sultanate of Shoa, had been destroyed in the fourteenth century by the Ethiopian negus Amda Seyon . A smaller sultanate, the Sultanate of Ifat , controlled a few trading ports on the coast including Saylac and Adal in the following decades. In 1415, the Ethiopians invaded Ifat and defeated its armies under its sultan, Sa'd ad-Din , though they failed to maintain control over Adal itself.

In the mid-1520s, a fiery imam named Ahmad ibn Ibrihim al-Ghazi (known as Ahmad Gran, the Left-Handed, to the Ethiopians) conquered the region of Adal and launched a holy war against Christian Ethiopia under the leadership of Lebna Dengel . Supplied by the Ottoman Empire with firearms, Ahmad was able to defeat the Ethiopians at the Battle of Shimbra Kure in 1528 and seize control of the wealthy Amhara plateau , though the Ethiopians continued to resist from the Christian highlands. In 1541, the Portuguese, who had vested interests in the Indian Ocean, sent aid to the Ethiopians in the form of 400 musketeers; Adal, in turn, received 900 from the Ottomans.

Ahmad was initially successful against the Ethiopians while campaigning in the fall of 1542, killing the Portuguese commander Christopher da Gama in August that year. Portuguese musketry proved decisive in Adal's defeat at the Battle of Wayna Daga , near Lake Tana, in February 1543, where Ahmad was killed in battle. The Ethiopians subsequently retook the Amhara plateau and recouped their losses against Adal; the Ottomans, who had their own troubles to deal with in the Mediterranean, were unable to help Ahmad's successors. In 1577, the capital of the Adal Sultanate was moved to Harar, and a sharp decline in Adal's power followed.

The migration of the pagan Oromo (called the Galla by the Amhara) into the Horn of Africa affected both Adal and Ethiopia. The warlike Oromo tribes exhausted the Ethiopians in the latter part of the sixteenth century in war, and the weakened Adal sultanate was unable to cope; by 1660, the sultanate had disappeared.