An independence movement took place that was not limited to just North (outer) Mongolia but was a pan-Mongolian phenomenon. On 29 December 1911, Bogd Khan became the leader of the Mongol empire. Inner Mongolia became a contested terrain between Khan and the Republic. In general, Russia supported the Independence of Outer Mongolia (including Tannu Uriankhai) during the time of the Xinhai Revolution. Tibet and Mongolia then recognized each other in a treaty.