 Zanabazar returned to Mongolia from Tibet in 1651, and founded seven "aimags" (monastic departments) in Urga, later establishing four more.As a mobile monastery-town, it was often moved to various places along the Selenge, Orkhon and Tuul rivers, as supply and other needs would demand.During the Dzungar wars of the late 17th century, it was even moved to Inner Mongolia.