Arslan Khan Muhammad

Muhammad ibn Sulayman belonged to the western branch of the Kara-Khanids. His father, Sulayman ibn Dawud, was a grandson of Ibrahim Tamghach Khan, founder of the western Kara-Khanid state, and his mother was a sister of the Seljuk sultan Barkyaruq. This made Muhammad a nephew of Sanjar; later one of Arslan Khan's own daughters married Sanjar.

In 1102 Sanjar defeated and executed Qadir Khan Jibra'il ibn Umar, who had been laying claim to Khorasan, and placed Muhammad on the throne of Samarkand with the title Arslan Khan. In the early years he was briefly driven out by Umar Khan, and after his restoration Hasan ibn Ali, known as Sagun Beg, rose against him; the struggle ended in 1109 with the victory of Sanjar's army at the battle of Nakhshab. His rule rested on Sanjar's patronage, and some coins carry the Seljuk ruler's name beside his own.

Arslan Khan kept a personal army of about 12,000 men and campaigned against non-Muslim Turkic peoples, earning the honorific “ghazi”. V. V. Barthold suggested that some of these campaigns were aimed at the Kipchaks. Coins show that Ferghana was part of his domain, governed by his son Ahmad.

His most visible legacy is in Bukhara. He rebuilt the ruined citadel, strengthened the city's defences and turned his palace in the Darvazacha quarter into a madrasa for jurists, endowing it with a waqf. In AH 513 (1119/1120) he moved the festival prayer ground closer to the city, to the site of the abandoned Shamsabad. He had the congregational mosque moved farther from the fortress; when the first minaret fell onto the building, he built a sturdier one at his own expense. The mosque was completed in 1121/1122 and the surviving Kalyan minaret in 1127. He also began to rebuild Paykand and replaced a bridge between Sharg and Iskijkat with one of baked brick.

Toward the end of his reign Arslan Khan was paralysed. His deputy, his son Nasr, was killed in a conspiracy, and Ahmad, summoned from Turkestan, became co-ruler with his father. The khan asked Sanjar for help, but Sanjar did not halt his march and in 1130 took Samarkand, sending Arslan Khan to Balkh. The sources place his death in 1130, 1131 or 1132; he is thought to have been buried in Merv.

His brother Ibrahim ibn Sulayman briefly held the throne of Samarkand, after which Arslan Khan's son Mahmud became great khagan and ruled the western Kara-Khanids until his defeat at the battle of Qatwan in 1141.