Barkiyaruq

Following the death of his father Malik Shah I, Barkiyaruq was proclaimed sultan in Isfahan at age twelve. His claim was immediately challenged by his half-brother Mahmud I and his uncle Tutush I, initiating a decade-long succession war.

Barkiyaruq's forces defeated the army of his uncle Tutush I, the Seljuk ruler of Syria, near Rayy. Tutush was killed in battle, eliminating a major rival and securing Barkiyaruq's control over the eastern Seljuk domains.

Barkiyaruq fought a series of campaigns against his half-brother Muhammad I Tapar, who rebelled with support from the Abbasid Caliph. The conflict lasted for years, draining Seljuk resources and preventing a unified response to the First Crusade.

Barkiyaruq and Muhammad I Tapar agreed to a partition of the Seljuk Empire. Barkiyaruq retained the title of sultan and control over western Persia and Iraq, while Muhammad ruled the eastern provinces. The treaty temporarily ended the civil war.

Barkiyaruq died of tuberculosis at age 25 in Isfahan. His death left Muhammad I Tapar as the sole sultan, but the Seljuk Empire remained weakened by years of internal conflict and the ongoing Crusader presence in the Levant.