In 1256, Georgia was placed under the Mongol empire of Ilkhanate, centered on Persia (Iran). In 1259–1260, Georgian nobles, led by David Narin, rose against the Mongols, and succeeded in separating Imereti (western Georgia) from the Mongol-controlled eastern Georgia. David Ulu decided to join his cousin in rebellion, but was defeated near Gori and was once again forced to submit to Mongol rule. Beginning in 1261, the Caucasus became a theater of the series of conflicts fought between Il-Khanids and another Mongol empire of Golden Horde centered in the lower Volga with its capital at Sarai.