Mongol tribe that supported the Il-Khan Hülegü's rise to power and eventually provided the successors to the Il-Khan dynasty as rulers of Iraq and Azerbaijan. A Jalayirid dynasty made its capital at Baghdad (1336-1432).
Hasan Buzurg, founder of the dynasty, had served as governor of Anatolia (Rum) under the Il-Khan Abu Sa'id (reigned 1317-35). Following the death of Abu Sa'id, Hasan Buzurg competed for real control of the empire with his rival, the Chupanid amir Hasan Kücük ("the Small," so designated to distinguish him from Hasan Buzurg, "the Great"); they set up rival khanates. Soon afterward the empire broke down into local dynasties in Anatolia, Iran, Azerbaijan, Georgia, and Armenia.
Hasan Buzurg had, meanwhile, established his line in Baghdad, from which he conducted his agitation against the Chupanids. His son The most prominent of the Jalayirids, Sheikh Uways (1356-74) finally wrested control of Azerbaijan from the Süldüz Chupanids in 1360, creating a polity based on Arabian Iraq and Azerbaijan. He enlarged Jalayirid domains by seizing Azerbaijan (1360) and placing the Mozaffarid principality of Fars under his suzerainty (1361-64). In addition to this and other military exploits, he fostered trade and commerce and won renown as patron of poetry, painting, and calligraphy. He also undertook a number of architectural projects in Baghdad.
The dynasty, however, was beset by the westward migrations and invasions of various Turkic and Mongol tribes. The khans of the Golden Horde, successors of Batu, unsuccessfully attempted the conquest of Azerbaijan in 1356-59. The later Jalayirids, however, dissipated their energies in fruitless foreign adventures and fratricidal struggles.
During the reign of Sultan Ahmad Jalayir (1382-1410), Timur (Timur Barlas, or Tamerlane), a new conqueror from Central Asia, took Baghdad and Tikrit in 1393. Forcing Sultan Ahmad to leave Baghdad and seek the protection of the Mamluks of Egypt until Timur's death in 1405. Although Sultan Ahmad was able to reoccupy his capital briefly, Timur again besieged and sacked Baghdad in 1401, dealing it a blow from which it did not recover until modern times.
Timurid administration in Arabian Iraq, first under Timur and later under his grandson Abu Bakr, was sporadic and short-lived: they controlled the area during the years 1393-94, 1401-02, and 1403-05. After Timur's death, Sultan Ahmad Jalayir regained Baghdad for a time, but in 1410 he was killed in a dispute with his former ally, Kara Yusuf (1389-1420), chief of the Kara Koyunlu (Black Sheep) Turkmen tribal confederation from eastern Anatolia, who had just driven the Timurids out of Azerbaijan. The remnants of the Jalayirid dynasty were pushed south to Al-Hillah, Wasit, and Basra. They were finally extinguished by the Kara Koyunlu in 1432.