Editing Timeline of Mongolian history (section)

== 20th century ==
{| class="wikitable" width="100%"
! style="width:6%" | Year || style="width:10%" | Date || Event
|-
|1907 || || The [[Qing dynasty|Qing]] government implemented sinification policies.
|-
| rowspan="2" valign="top" | 1911 || 1 December || Outer Mongolia declared independence from the [[Qing dynasty]] under the [[Bogd Khan]].
|-
| 29 December || The Bogdo [[Khanate]] of Mongolia was proclaimed and [[Bogd Khan]] enthroned.
|-
| 1912 || 3 November || The [[Russian Empire]] recognized Mongolian independence and the rule of [[Bogd Khan]].
|-
| 1913 || 11 November || Mongolia and [[Tibet (1912–1951)|Tibet]] concluded treaty on mutual recognition and mutual assistance.
|-
| 1915 || || [[Russian Empire|Russia]], [[Republic of China (1912–1949)|China]] and Mongolia signed a treaty at [[Kyakhta]] under which China was recognized as sovereign over an autonomous Mongolia.
|-
| 1919 || || Outer Mongolia was occupied by the [[Republic of China (1912–1949)|Republic of China]].
|-
| rowspan="4" valign="top" | 1921 || || The [[Soviet Union|Russian]] [[Red Army]], with the support of [[Damdin Sükhbaatar]], defeated the forces of [[Roman Ungern von Sternberg]].
|-
| February || [[Roman Ungern von Sternberg|Ungern]] drove [[Republic of China (1912–1949)|Chinese]] troops out of [[Ulaanbaatar|Niislel Khuree]].
|-
| March || All remaining [[Republic of China (1912–1949)|Chinese]] troops were defeated by [[Roman Ungern von Sternberg|Ungern]] and driven from Mongolia, allowing the reassertion of Mongolian independence under [[Bogd Khan]].
|-
| 18 March || [[Mongolian People's Party|Communist]] guerrillas headed by [[Damdin Sükhbaatar]], with the assistance of [[Red Army]] troops, defeated the [[Republic of China (1912–1949)|Chinese]] garrison in the Mongolian settlement Maimachen near [[Kyakhta]].
|-
| 1924 || 26 November || After the death of the [[Bogd Khan]], the [[Mongolian People's Republic]] was declared in Outer Mongolia.
|-
| 1928 || || Collectivization began.
|-
| 1932 || || The failure of collectivization led to widespread uprisings and a temporary thaw.
|-
| 1936 || || Prince [[Demchugdongrub]] formed the [[Mengjiang|Mongol Military Government]], a non-Communist state independent from [[Republic of China (1912–1949)|China]], in Inner Mongolia.
|-
| rowspan="2" valign="top" | 1937 || || The [[Mengjiang|Mongol Military Government]] was renamed the Mongol United Autonomous Government.
|-
| || ''[[Stalinist purges in Mongolia]]'': A [[Stalinism|Stalinist]] terror began which would lead to the deaths of more than thirty thousand people in the Mongolian People's Republic.
|-
| rowspan="3" valign="top" | 1939 || || ''Stalinist purges in Mongolia'': The terror ended.
|-
| May || ''[[Battle of Khalkhyn Gol]]'': Large scale fighting took place between [[Empire of Japan|Japanese]] and joint [[Soviet Union|Soviet]]-Mongolian forces along [[Khalkhyn Gol]] on the border between Mongolia and [[Manchuria]].
|-
| 16 September || ''Battle of Khalkhyn Gol'':  The battle ended in a [[Empire of Japan|Japanese]] defeat.  A truce was negotiated between Japan and the [[Soviet Union]].
|-
| 1941 || || The [[Mengjiang|Mongol United Autonomous Government]] was renamed the Mongolian Autonomous Federation, or Mengjiang.
|-
| rowspan="3" valign="top" | 1945 || August || The [[Republic of China (1912–1949)|Republic of China]] requested [[Soviet Union|Soviet]] help in the war against [[Empire of Japan|Japan]], and offered recognition of the independence of Outer Mongolia in exchange according to the [[Sino-Soviet Treaty of Friendship and Alliance]].
|-
| August || The Mongolian People's Republic declared war on [[Empire of Japan|Japan]], one day after the [[Soviet Union]], and began to liberate [[Southern Mongolia (region)|Southern Mongolia]] from the China and the Japan.
|-
| October || A plebiscite yielded a 100% pro-independence vote.
|-
| 1946 || January || The [[Republic of China (1912–1949)|Chinese]] government recognized the independence of Mongolian People's Republic.
|-
| 1949 || 6 October || The newly established [[People's Republic of China]] recognized Mongolia and agreed to establish diplomatic relations.
|-
| 1950 || || Herds were successfully collectivized.
|-
| 1952 || || The [[Republic of China|Republic of China (ROC)]] on [[Taiwan]] renounced the [[Sino-Soviet Treaty of Friendship and Alliance]].
|-
| 1955 || || The [[Republic of China|ROC]] blocked the accession of the Mongolian People's Republic's entry to the [[United Nations]].
|-
| rowspan="2" valign="top" | 1961 || || The Mongolian People's Republic entered the [[United Nations]].
|-
| || The [[Trans-Mongolian Railway]] was finished.
|-
| rowspan="2" valign="top" | 1962 || || Mongolia became a member of the [[Comecon]].
|-
| || ''[[Sino-Soviet split]]'': The [[Mongolian People's Party|Communist Party]] leadership sided with the [[Soviet Union]] in a falling-out with [[China]].
|-
| 1965 || || [[Yumjaagiin Tsedenbal]] purged the intelligentsia.
|-
| 1969 || || ''Sino-Soviet split'': The [[Soviet Union]] stationed a large army on Mongolian territory in response to threats of [[China|Chinese]] aggression.
|-
| 1981 || March || [[Jügderdemidiin Gürragchaa]] became the first Mongolian in space.
|-
| 1984 || August || [[Yumjaagiin Tsedenbal|Tsedenbal]] resigned.
|-
| 1987 || 27 January || Mongolia established diplomatic relations with the [[United States]].
|-
| rowspan="2" valign="top" | 1989 || July || The first Mongolian member of the [[Baháʼí Faith]] entered the country.
|-
| December || The first popular reform demonstrations took place; the Mongolian Democratic Association was organized.
|-
| rowspan="5" valign="top" | 1990 || January || Large-scale pro-democracy demonstrations were held in sub-zero weather.
|-
| 2 March || Mongolia and the [[Soviet Union]] announced that all Soviet troops would be withdrawn from Mongolia by 1992.
|-
| May || The constitution was amended to provide for a multi-party system and new elections.
|-
| 29 July || The first democratic elections were held. The [[Mongolian People's Party|Communist Party]], now the Mongolian People's Revolutionary Party (MPRP), won.
|-
| 3 September || The first democratically elected People's Great Hural took office.
|-
| rowspan="3" valign="top" | 1992 || 13 January || A new constitution went into effect.
|-
| 8 April || A new election law was passed.
|-
| 28 June || An election was held for the first unicameral legislature, the State Great Hural. The [[Mongolian People's Party|MPRP]] won.
|-
| 1993 || 6 June || The first direct presidential election took place. Opposition candidate [[Punsalmaagiin Ochirbat]], a former [[Mongolian People's Party|MPRP]] member, won.
|-
| 1996 || 30 June || The first non-[[Mongolian People's Party|Communist]] government was elected.
|-
| 1998 || || [[Sanjaasürengiin Zorig]], Minister of Infrastructure and one of the leaders of the 1990 protests, was murdered.
|-
| 2000 || 2 July || The [[Mongolian People's Party|MPRP]] was elected; a new government was formed by Prime Minister [[Nambaryn Enkhbayar]].
|}