The Seljuk Empire

¹ Tughril Beg and his brother Chaghri Beg led the Oghuz Turkic Seljuk clan from the Central Asian steppe into Khorasan. Tughril entered Baghdad in 1055 as the Abbasid caliph’s protector, receiving the title Sultan and restoring Sunni political supremacy over the Shi’a Buyids who had dominated the caliphate for a century.

² Tughril died without a surviving son, so the throne passed to his nephew Alp Arslan, son of his brother Chaghri Beg. Alp Arslan crushed a Byzantine army at the Battle of Manzikert in 1071, a defeat that opened Anatolia to permanent Turkic settlement and reshaped the map of the medieval Middle East.

³ Malik-Shah I’s reign, guided by the great vizier Nizam al-Mulk, is usually seen as the height of Seljuk power. Nizam al-Mulk also sponsored the astronomical observatory whose calendar reform is associated with the poet-mathematician Omar Khayyam.

⁴ After Malik-Shah I’s death the empire fractured repeatedly among his sons and grandsons. Ahmad Sanjar, who had governed Khorasan since 1097, eventually secured recognition as supreme sultan but was captured by rebellious Ghuzz tribesmen in 1153 and died a broken figure in 1157 — the effective end of unified Great Seljuk authority over Iran.

⁵ A western branch, the “Seljuks of Iraq,” continued ruling parts of western Iran and Iraq under a rapid, poorly documented sequence of minor and often child sultans for another four decades. The last of them, Toghrul III, was defeated and killed in 1194 by Ala al-Din Tekish, shah of the rising Khwarazmian Empire, which absorbed the remaining Seljuk lands in Iran.