Sultan of the Great Saljûq Empire (1092-1094).
Mahmūd I was the youngest son of the Saljûq sultan Malik Shāh I. When his father died at Baghdad in December 1092, Mahmūd I was the only son in his company. Mahmūd’s mother Terken Khātūn, a Qarakhanid princess, at once managed to secure his recognition as sultan from the ‘Abbāsid caliph al-Muqtadī, who granted him the honorific Arabic title Nāsir al-Dunya wa al-Dīn (“Victorious in the Secular World and in Religion”).
In ruling the Saljûq Empire, Mahmûd was assisted above all by two men: Unar, commander of the Saljûq armies, and the vizier Tāj al-Mulk. Terken Khātūn secured the loyalty of the army through lavish spending from the royal treasury. During 1093, she and Mahmûd captured Isfahan, the Saljûq capital, and arrested Barkyârûq, Mahmûd’s brother and rival. However, Barkyârûq was released by a group of his father’s commanders. He defeated Mahmûd’s army at Baru- jerd and was recognized as sultan by the new ‘Abbāsid caliph. In September 1094 Terken Khāton died suddenly; Mahmûd died soon afterward, in circumstances that are unclear.