rces on Mangystau Region date back to the 9th century AD.[citation needed] According to Arabic geographers, it was uninhabited until the tenth century when groups opposing the Turkmen Oghuz settled and found sources of water and grassland. The mountain called Binkishlah (unidentified) would have marked the border between Khwarezm and the Khanate of the Khazars. These Turkmen were vassals of the Khazars, at the beginning of the thirteenth century when Yaqut al-Hamawi and Ibn al-Athir mention[citation needed] the name of Mankashlagh. Ibn al-Athir tells of a Turkish principality with a medina with the same name as the territory that existed from the late eleventh century. In 1097 a struggle between Kutb al-Din Muhammad, Khwarezm governor of Seljuks and Tugrul Tehghin occurred. In 1127, Atsiz occupied the whole peninsula. During Khwarezmshah rule, it was part of firstly Gorgan province, later Mazandaran Province. In 1221, the Mongols occupied it. It was later passed to successively Golden Horde, Nogai Horde, Uzbek Khanate and Kazakh Khanate, but its population decreased after gradual drying of the steppe and Kalmyk raids began in 1620. Some Salur and Ersari Turkmens left the region and migrated to Russia. Ustyurt Plateau Zhabayushkan Reserve In 1670, Anusha Khan who was the khan of Khiva asked the Russian government to build a fortress to protect the peninsula for securing trade between Russia and Khwarezm. Puntsuk Monchak and Ayuka (1670–1724) deported most of the Cawdor and Igdir groups of Turkmenistan to the Volga basin. For protecting trade, Anusha Khan annexed it to his territories in 1676 and built a fort at the port of Karagan in 1687. The Russians under Peter the Great sent an expedition led by the unfortunate Bekovich-Cherkassky, who established three forts on the coast of the Caspian Sea, but they were abandoned after one y