Dzhanids, a dynasty of Bukhara khans (1599–1753) descended from the Astrakhan khans of the house of Dzhuchi. It succeeded the Sheibanid dynasty in Bukhara. The most prominent representatives of the Ashtarkhanids were Imam-kuli (1611–2), Nadir Mukhammed (1642–45), Abd-al-Aziz (1645–80), Subkhan-kuli (1680–1702), Ubaidulla II (1702–11), and Abu al-Faiz (1711–47). Ashtarkhanid rule was marked by a bitter struggle for power between the major Uzbek tribes and the khans in Bukhara and Khorezm. The Kara-Kalpaks, Kazakhs, and Kalmyks were drawn into the lengthy struggle. This struggle ended with the replacement of the Ashtarkhanids by the Mangyt dynasty in Bukhara and the establishment of Kungrat rule in Khorezm.