20th Century Mongolia By Sam Howe Dec 1, 1911 Outer Mongolia proclaims independence from China Outer Mongolia proclaims independence from China Period: Dec 1, 1911 to Mar 7, 1989 20th Century Mongolia Dec 28, 1911 Mongolia establishes autonomous theocratic government Nov 3, 1912 Russia affirms Mongolia's separation from China Nov 5, 1913 Sino-Russian agreement acknowledges Chinese suzerainty over Mongolia May 25, 1915 Treaty of Kyakhta formalizes Mongolian autonomy Sep 1, 1918 Chinese troops occupy Outer Mongolia Period: Mar 1, 1920 to Jun 1, 1920 Mongolian People's Party formed, establishes links with Communist International and Soviets Oct 1, 1920 Russian White Guards invade Mongolia Mar 2, 1921 First National Party Congress of the Mongolian People's Party held in Kyakhta, Soviet Union Mar 13, 1921 Mongolian People's Provisional Government formed Jul 1, 1921 Mongolian-Soviet army drives out White Guards Jul 11, 1921 Mongolian People's Government, a limited monarchy, proclaimed Sep 14, 1921 Mongolian independence proclaimed Nov 5, 1921 Soviets recognize Mongolian People's Government Feb 22, 1923 Revolutionary hero Damdiny Sukhe Batar dies May 31, 1924 Sino-Soviet treaty recognizes Chinese sovereignty over Mongolia Aug 1, 1924 Mongolian People's Party becomes Mongolian People's Revolutionary Party Nov 6, 1924 November 6, 1924First National Great Hural convenes Nov 25, 1924 Mongolian People's Republic proclaimed; Soviet style state constitution adopted; Niyslel Huree renamed Ulaanbaatar Mar 1, 1925 Soviet troops ostensibly withdraw Sep 13, 1927 Inner-party struggle at Sixth Party Congress Dec 1, 1928 Horloyn Choybalsan emerges as party leader Period: Jan 1, 1929 to Dec 31, 1932 Feudal estates confiscated; religious communities suppressed May 13, 1932 Soviet troops help quell rebellions; party repudiates extremism Nov 27, 1934 Mongolian-Soviet "gentlemen's agreement" allows Soviet troops into Mongolia Mar 12, 1936 Treaty and mutual defense protocol signed with Soviet Union Period: Jan 1, 1937 to Dec 31, 1939 High-level government purges Aug 1, 1939 Mongolian-Soviet joint force defeats Japanese at Khalkhyn Gol Aug 10, 1945 Mongolia declares war on Japan Jan 5, 1946 China recognizes Mongolia's independence Feb 27, 1946 Treaty of Friendship and Mutual Assistance and Agreement on Economic and Cultural Cooperation signed with Soviet Union Dec 13, 1952 Economic and cultural cooperation agreement signed with Chin Jul 6, 1960 New state Constitution adopted Oct 27, 1961 Mongolia admitted to United Nations Jun 7, 1962 Mongolia joins Council for Mutual Economic Assistance Jan 15, 1966 Serious Mongolian-Chinese differences emerge Apr 13, 1986 Long-term trade agreement signed with China Jan 15, 1987 Soviet Union announces intention to withdraw one of five Soviet divisions stationed in Mongolia Jan 27, 1987 Diplomatic relations established with the United States Nov 28, 1988 Treaty on a border control system signed with China Mar 7, 1989 Soviets announced that troop withdrawal plans had been finalized