| 1911 | July | Participants at anti-Chinese meeting in Yihe Huree petition the Russia for assistance in the effort to gain Mongolia’s independence from China. |
| December 1 | Outer Mongolia proclaims its independence, declaring that its allegiance has been to the deposed Manchu emperors and not to China. |
| December 28 | The 8th Jebtsundamba Khutuktu becomes Bogdo Khan of an autonomous theocratic government. Yihe Huree is renamed Niyslel Huree (capital city). A 20,000 man Mongol army is formed and Russian officers arrive to organize, train and equip it. China refuses to recognize Mongolian independence but its new government is preoccupied with internal discord and takes no measures to enforce its sovereignty. |
| 1912 | November 3 | A Mongolian-Russian agreement and protocol signed in Niyslel Huree affirms Mongolian autonomy and establishes a Czarist protectorate over Outer Mongolia. |
| December 19 | Mutual recognition of independence is granted by the governments of Mongolia and Tibet in agreements signed in Niyslel Huree. |
| 1913 | November 5 | A Sino-Russian accord recognizes Chinese suzerainty over Mongolia. China agrees not to send troops to Mongolia and recognizes Outer Mongolia's right to autonomy and control of its commerce and industry. |
| 1915 | May 25 | China, Russia and Mongolia sign the Treaty of Kyakhta which formally establishes Mongolian autonomy. |
| 1919 | February – March | The Japanese backed Pan-Mongolia Conference in Chita, Siberia forms a provisional government to press the Versailles Conference for recognition of a Mongol state comprising Outer Mongolia, Inner Mongolia, and Buryatia. Outer Mongolia refuses to participate in the government. The movement fails in the face of renewed Chinese efforts to regain control of all Mongolia |
| October | A Chinese army under warlord General Hsu Shu-cheng occupies Niyslel Huree. The Bogdo Khan government acknowledges Chinese sovereignty. The Mongol army is disarmed and disbands. |
| During the Year | Two secret revolutionary circles emerge in Niyslel Huree, Damdiny Sukhe Bator’s Dzuun Huree militia and the Horloogiyn Dandzan (Consul's Group) led by Horloyn Choybalsan and Dogsomyn Bodoo. Comintern advises the two groups to merge in order to present a united front to the Chinese and the White Russian occupation forces. |
| | A pro-Japanese “Greater Mongolia” government is formed in Dauria. |
| 1920 | March | A conference in Irkutsk, Siberia results in the merger of the Dzuun Huree militia and the Horloogiyn Dandzan (Consul's Group) as the Mongolian People's Party under the leadership of Sukhe Bator. The 8th Jebtsundamba Khutuktu supports the revolutionary leaders and they appeal for increased Soviet assistance in his name. |
| October | Russian White Guards under Baron Roman Nicolaus von Ungern-Sternberg invade Mongolia from Siberia. The Japanese finance von Ungern-Sternberg in an attempt to limit Soviet influence over Mongolia. |
| During the Year | Mongolyn Ünen (Mongolian Truth) is established as the official organ of the Mongolian People’s Party. The paper is renamed several times; Uria (Call) and Niysleliyn Shine Sonin (Capital’s New Newspaper) before settling on Ünen (Truth) in 1925. |
| 1921 | February | Von Ungern-Sternberg’s White Guards drive the Chinese out of Niyslel Huree and occupy the city after a fierce battle. Mongolian monarchists hail von Ungern-Sternberg as a liberator but during the next several months the White Guards engage in a reign of terror and destruction that arouses opposition in the populace. |
| February 9 | Sukhe Bator establishes the Mongol Ardyn Juramt Tsereg (Mongolian Partisan Army). |
| March 1 to 3 | The First Congress of the Mongolian People's Party meets in Kyakhta, Siberia. The Party adopts a program titled the “Ten Aspirations”. Aspiration #6 calls for, “preservation of policies, religion, and customs in the people’s interest or their elimination if backward or harmful”. |
| March 13 | Sukhe Bator's Mongolian Partisan Army captures Khiagt. The Central Committee of the Mongolian People's Party forms the Mongolian People's Provisional Government and establishes its capital at Khiagt. |
| July | Sukhe Bator's Mongolian Partisan Army drives von Ungern-Sternberg's forces out of Niyslel Huree and occupies the city. |
| July 11 | The Bogdo Khan government is replaced by a limited monarchy nominally headed by the 8th Jebtsundamba Khutuktu. Bodoo is named premier and foreign minister of the new People's Government of Mongolia. Sukhe Bator becomes minister of war and continues as Commander in Chief of the Mongolian Partisan Army with Choybalsan as his deputy. Soviet troops occupy the country in support of the new regime. |
| August 22 | Mongolian forces capture the leader of the Russian White Guards, Baron von Ungern-Sternberg at Tarialan. The Baron is turned over to the Soviets and executed. |
| September 14 | The People's Government of Mongolia declares its independence from China. |
| September | The Red Army’s 185th Cavalry lifts the siege of Saruul Güngiyn Huree on the shores of Lake Talbo. 300 Mongol and Soviet troops under General Hasbataar held the monastery against 44 days of attacks by 3000 Russian White Guards under Baron von Ungern-Sternberg. |
| October 26 | The first session of the National Provisional Little Hural (legislature) convenes. Normalization of Mongolian-Soviet relations is accelerated. |
| November 5 | An Agreement on Mutual Recognition and Friendly Relations is signed in Moscow. The Soviets grant diplomatic recognition to the People's Government of Mongolia and both parties agree to support the self-determination of Tannu Tuva. |
| November | Supporters of the Bogdo Khan express displeasure with limits placed on the monarchy. The ruling Mongolian People's Party responds with further restrictions on the powers of the Bogdo Khan. |
| 1922 | January | The last of Baron von Ungern-Sternberg’s White Guards are defeated. |
| August | 41 leading party functionaries are arrested and charged with “counterrevolutionary activities” and attempting to restore the autocratic powers of the Bogdo Khan. |
| August 31 | Former Prime Minister and Party Chairman Dagsomym Bodoo, former Prime Minister Dambyn Chadarjav and 13 others are executed. Bodoo has expressed concern over growing Soviet influence in Mongolia. |
| 1923 | February 22 | Revolutionary hero Sukhe Bator dies of illness at age 33 clearing the path for Horloyn Choybalsan's rise to power. (Choybalsan claims that Bator had been poisoned). |
| July | The Second Party Congress of the Mongolian People's Party reiterates the need for Mongolian-Soviet solidarity and calls for a purge of, “oppressor class elements” from the ranks. |
| 1923 – 1924 | Exports of livestock and animal products account for 14% of Mongolia’s gross national product. |
| 1924 | May 20 | The 8th Jebtsundamba Khutuktu dies. The People's Government forbids the traditional search for his reincarnation in order to eliminate the symbol of theocratic power over Mongolia. |
| May 31 | A new Sino-Soviet treaty provides for the withdrawal of Soviet troops in Mongolia. |
| August 4 to 24 | The Third Party Congress of the Mongolian People's Party meets in Niyslel Huree. Party chairman Horloogiyn Dandzan leads a faction favoring reduced Soviet influence in Mongolia. The Congress renames the party the Mongolian People's Revolutionary Party and conducts a purge of “useless elements” and concludes with the arrest and execution of the “capitalist” Dandzan. |
| November 25 | The Mongolian People's Republic is formally established with the adoption of a Soviet-style constitution by the First National Great Hural. The National Minor Hural is elected to serve as the standing body of the National Great Hural when it is not in session. It, in turn, elects a cabinet with Balingiyn Tserendorj as premier and Horloyn Choybalsan as commander in chief of the army. The capital city, Niyslel Huree, is renamed Ulaanbaatar (The Red Hero). |
| During the Year | The Soviet Union explicitly recognizes Mongolia's independence of China in internal affairs and its right to pursue an independent foreign policy and declares that it will permit no Chinese encroachments. Mongolia acknowledges strong ties to the Soviet Union as, “the reliable pillar of independence and prosperity”. |
| | The Mongolian National Bank is established as a joint Mongolian-Soviet company. |
| | A standardized tax system is instituted and other administrative reforms take hold. |
| 1925 | January | The Ih Shav’ Buddhist estates in Northern Mongolia are reorganized as Dleger Ih Uul Province. |
| March | The Soviet Union announces withdrawal of its troops from Mongolia. |
| May | Mongolian Civil Air Transport (Mongol irgeniy agaaryn teever) is established as the national airline. MIAT begins carrying airmail, freight and passengers between Ulaanbaatar and Kyakhta, Siberia and Ulan-Ude in the Soviet Buryat Republic using Junkers Ju-13 monoplanes supplied by Soviet Russia. |
| May | The Mongolian Pioneers (Communist Youth) Organization is formed. |
| September | The Fourth Congress of the Mongolian People's Revolutionary Party adopts the party’s Second Program which calls for, “bringing the Democratic Revolution to its conclusion and implementing the general line of developing the country along the noncapitalist path”; eradicating remaining, “secular and ecclesiastical reactionaries” and “oppressive” foreign traders and moneylender and; creation of a new economy to strengthen national independence. |
| December | The Mongolian National bank issues a new national currency, the Tugrik. |
| 1925 - 1928 | The government refrains from direct attacks on the religious establishment and the number of monks actually increases but some higher-level clerics are arrested and executed. |
| | Many nobles retain their wealth and nearly 90% of all trade is controlled by Chinese firms. |
| 1926 | August | A Treaty of Friendship is signed with the Tuvinian People’s Republic. |
| September | The Fifth Congress of the Mongolian People’s Revolutionary Party calls for restrictions on private capital and development of national and cooperative property. |
| 1927 | January | The Mongolian State Supreme Court is established. |
| March | Stormong (Mongolian Soviet Trading) Company is formed to handle all Mongolian exports. |
| During the Year | Mongolia’s resident Chinese population drops 27% to 17,496. |
| | Mongolia’s resident Russian population increases 68% to 2,969. |
| 1928 | December 10 | The Seventh Congress of the Mongolian People's Revolutionary Party ends in a decisive victory of the Left. Party chairman TserenOchiryn Dambadorj is exiled to Moscow and other rightist members are expelled. |
| December | The Fifth National Great Hural ratifies the leftist program for developing Mongolia on a socialist line put forth at the party congress. The Hural calls for immediate confiscation of feudal property, development of a 5 Year Plan, collectivizing livestock herders, the ouster of Chinese trading firms and imposition of a Soviet trade monopoly. Conservative officials are eliminated from the government and Horloyn Choybalsan is chosen to head the National Minor Hural. |
| During the Year | The Tugrik is made the only legal tender currency. Use of foreign currencies, the Maria Theresa thaler and gold rubles is outlawed but silver ingots and tea bricks remain a common medium of exchange. |
| 1928 – 1929 | The Soviet grip on the Mongolian economy tightens. Exports to the Soviets rise to 85% of Mongolia’s gross national product. |
| 1929 | September | Over 600 feudal estates are confiscated and given to members of the laity and monks who leave their monasteries. |
| December | Mongoltrans, a Soviet-Mongolian joint stock company, is established to operate road and river transport and build roads and bridges. The Soviets supply 50 vehicles and a repair shop. |
| 1930 | February - April | The Eighth Party Congress of the Mongolian People's Revolutionary Party recognizes that the country is unprepared for total socialization but the leadership decides to reinforce its measures. The massive shift from private property to collectivization is accelerated. |
| March | A counter-revolutionary uprising by Tögsbuyant and Ulaangom lamas is suppressed. |
| April | The Sixth Great Hural approves introduction of a Romanized alphabet to replace the traditional 24 character Mongolian script. The new alphabet contains 6 special letters (È, Ì, Î, S^, Ö and Ü) in addition to the 26 letters of the Latin alphabet. |
| During the Year | The party attacks the monastic class, the nobility, the nomads, and the nationalists and conducts a purge of its own ranks. The government imposes high taxes, confiscates private property, bans private industry, forces artisans to join cooperatives, and nationalizes trade and transportation. The power of the monks and the feudal nobles is broken, Chinese traders are ousted and dependence on Soviet aid grows. |
| | MIAT establishes air routes linking Ulaanbaatar with Hovd via Tsetserleg and Uliastay and with Bayantümen using Polikarpov R-1 aircraft (Soviet versions of the DH-9). |
| | Mongoltrans begins operating a bus service in Ulaanbaatar. |
| 1930 – 1932 | Sheep and cattle herders angered by forced collectivization slaughter of 7 million animals. The failure of collectivization, rapid destruction of private trade and inadequate Soviet aid contribute to a spreading famine. Thousands suffer from severe food shortages. Mongolia verges on the brink of civil war. |
| 1931 | | More than 1/3 of the stock-raising households have been forcibly collectivized. The rapid and often brutal collectivization of herdsmen that follows expropriation of the feudal estates leads to bloody uprisings. |
| September 18 | The Mukden Incident opens the way for establishment of the Japanese puppet regime in Manchuria, “Manchukuo”. Rumors of Japanese plans for a similar regime, “Mengkukuo” in Mongolia alarms Ulaanbaatar. |
| 1931 – 1932 | The property of more than 800 religious and secular leaders is seized. Over 700 heads of households are killed or imprisoned. A three pronged antireligious campaign is launched. Ordinary monks are forced to leave the monasteries and enter the army or the economy. Middle level monks are put in prison camps. Those of highest rank are killed. |
| 1932 | April | The Mongolian government calls in troops and tanks to suppress anti-communist uprisings in western Mongolia. The rebellion is crushed with Soviet assistance. |
| May | Comintern directs the Mongolian party to end its extremist program. |
| June | The Central Committee of the Mongolian People's Revolutionary Party rejects its prior policies as “leftist deviation” and expels several top leaders as “leftwing adventurers.” Horloyn Choybalsan declares, “overall development of our country has not yet entered the stage of socialism and it is wrong to copy Soviet experience in all things.” |
| June | The New Turn Policy of socioeconomic gradualism is introduced. Collectivized agriculture and worker cooperatives are abandoned. Herders and peasants are allowed to own private property again and the cattle tax is reduced. However, foreign trade remains under state control and continues to be channeled exclusively to the Soviet Union. |
| 1933 | February | Mongol Radio begins regularly scheduled broadcasts from Ulaanbaatar. |
| December | Japan claims Outer Mongolia as part of Manchukuo following it seizure of China’s Jehol Province. |
| 1934 | September | MIAT establishes air routes linking Ulaanbaatar with Zamyn-Üüd and Altay using civilianized R-5 military biplanes. |
| September - October | The Ninth Congress of the Mongolian People's Revolutionary Party pronounces the New Turn policy a success. |
| November 27 | A Mongolian-Soviet “gentlemen's agreement” is reached providing for mutual assistance in the face of Japanese advances in Manchuria and Inner Mongolia. |
| During the Year | The Law of Separation of Church and State is amended to ban religious instruction in schools, entrance of novices to monasteries and extend conscription for military service to monks. A heavy tax is placed on monasteries. |
| 1935 | January | Soviet troops reenter Mongolia in response to Japanese probes on the Mongolian-Manchurian border. |
| December | Mongolian troops clash with Japanese forces from Manchukuo in the Buyr Nuur border region. |
| | A law is enacted requiring lamas to, “work for society”. |
| 1936 | March 12 | The 1934 Soviet-Mongolian agreement is upgraded with by signing of a 10 year Treaty of Friendship which includes a mutual defense protocol. The pact does not mention Chinese sovereignty over Mongolia, and Moscow ignores China’s protests. |
| During the Year | The Soviet-Mongolian joint stock company operating the Mongolian National Bank turns the bank over to the Mongolian government. |
| | Military expenditures double. Soviet aid finances construction of paved roads, airfields and extended rail and communication lines. |
| 1937 | | A rebellion at the Yögzör monastery precipitates further government crackdowns. 60 monasteries are closed, about 2,000 abbots and other high ranking monks are executed and thousands more are arrested and imprisoned. |
| August | Marshal Demid is poisoned while aboard the Trans-Siberian Railway. |
| November | The Ulaanbaatar-Nalayh narrow gauge railway goes into operation. |
| 1937 - 1939 | A Special Commission to fight espionage and counterrevolution headed by Interior Minister Horloogiyn Choybalsan investigates 25,824 cases. 20,474 of the accused are sentenced to execution, 5,103 to 10 years imprisonment, 240 to lesser prison sentences and 7 people are exonerated. |
| | Minor rebellions continue. Uncooperative politicians accused of aiding the opposition or the Japanese are purged from the party. |
| 1938 | | Mongolia spends over half of its budget for defense. |
| 1939 | | Horloyn Choybalsan emerges as premier, minister of war, and the undisputed leader of Mongolia. |
| | The Japanese seek the approval of the Dalai Lama to search for the incarnation of the 9th Jebtsundamba Khutuktu in Inner Mongolia. The Mongolian government has forbidden a search for the successor to the 8th Jebtsundamba Khutuktu who died in 1924. |
| March 7 | Prime Minister and Foreign Minister Anandyn Amar is accused of counterrevolutionary activity by chairman Horloyn Choybalsan at a meeting of the Presidium of the Mongolian People’s Revolutionary Party. Amar is dismissed as Prime Minister and expelled from the party. |
| May | Japanese forces based in Manchukuo invade eastern Mongolia. |
| May –September | Soviet General Georgi Zhukov commands the Soviet-Mongolian army that meets the invasion. There is large-scale ground and aerial fighting along the Khalkhyn Gol, a river in northeastern Mongolia. Mongolian troops and their Soviet allies hand the enemy a severe defeat. The Japanese sustain an estimated 80,000 casualties against 11,130 by the Mongolians and Soviets. |
| July | Former Prime Minister Amar is turned over to the NKVD in Chita, Siberia. |
| September 16 | The Soviet Union and Japan sign a truce and a commission is set up to define the Mongolian- Manchukuo border. Japan continues to mass large military forces along the Mongolian and the Soviet borders during the war but does not invade again. |
| During the Year | The Bayantümen-Ereentsav railway goes into operation. |
| 1939 - 1945 | The Soviet position in Mongolia is fully consolidated. Choybalsan follows Moscow's directives throughout World War II. Mongolia supports the Soviet Union with livestock, raw materials, money, food, and military clothing. The Mongolian army, estimated to number between 80,000 and 100,000 men, remains mobilized for the duration of the war. |
| 1940 | March - April | The Tenth Congress of the Mongolian People's Revolutionary Party adopts the party’s Third Program calling for the uprooting of the remnants of feudalism and “development along the noncapitalist path in order to prepare for entering socialism”. The Congress approves the appointment of Yumjaagiyn Tsedenbal as party general secretary but Choybalsan continues to be its predominant force. |
| April | The Eighth National Great Hural adopts a new constitution which emphasizes the new Mongolian authority structure, the bypassing of capitalism, and the necessity of overall state planning but makes no basic alterations to the 1924 constitution Private ownership, especially of livestock, continues to be permitted. |
| July | The 32 letter Romanized alphabet officially replaces the 24 character traditional Mongolian script. |
| 1941 | April 13 | The Soviet-Japanese Neutrality Pact is signed. Japan promises to respect Mongolia's territorial integrity. |
| July 10 | Former Mongolian Prime Minister Amar is convicted of spying for the Japanese and sentenced to death by the Military Collegium of the Supreme Court of the Soviet Union. |
| July 27 | Former Mongolian Prime Minister Amar is executed in Moscow. |
| During the Year | An estimated 90% of the population is illiterate. |
| 1942 | October | The country's first university, Choybalsan University, is established in Ulaanbaatar. |
| 1943 | January | The Revolyutsionnaya Mongoliya tank regiment is handed over to the Red Army by a visiting Mongolian delegation to Moscow. |
| March | The Cyrillic alphabet replaces Mongolia’s 32 letter Romanized alphabet. |
| September | The Mongolian Arat Fighter Squadron is presented to the Soviet Air Force in a formal ceremony. Mongolia has supplied the funds to pay for the squadron’s 12 Lavochkin La-5 fighters. |
| 1945 | August 10 | Mongolia also declares war on Japan 2 days after the Soviet Union declares war on Japan. The Mongolian army joins Soviet troops in invading Inner Mongolia and Manchuria. |
| August 14 | A Sino-Soviet Treaty of Friendship and Alliance is signed. China agrees to recognize the independence of Mongolia within its "existing boundary" provided that a plebiscite confirms the Mongolian people's desire for independence. |
| October 20 | Mongolia announces that 100% of the electorate has voted for independence from China. |
| 1946 | January 5 | China recognizes Mongolian independence. |
