China controlled this vast Central Asian steppe and mountain region for more than two centuries until the overthrow of the Qing dynasty in 1911, and then again from 1919 to 1921, when Soviet-backed Marxists successfully rebelled against Chinese rule. Following three years of nominal rule by Buddhist lamas, the Mongolian People’s Revolutionary Party (MPRP) formed a single-party Communist state in 1924. For the next 65 years, the Soviet Union controlled Mongolia’s politics and economy. In December 1989, a group of academics and students defied the regime by forming the opposition Mongolian Democratic Union (MDU). In early 1990, the MDU formed the country’s first opposition political party, the Mongolian Democratic Party. The government amended the constitution in May 1990 to end the MPRP’s status as the sole legal political party following a series of MDU-organized street protests and hunger strikes.