||White Russian Occupation of Mongolia
||A Mongolian army, under the leadership of the White Russian Baron Ungern von Sternberg, forced the Chinese army to evacuate Outer Mongolia. As a result, the Chinese lost their suzerainty over the province.
|January 1, 1921
||French reorganized the administration of French West Africa and created the colony of Mauritania in West Africa.
|January 18, 1921
||British Evacuation of Persia
||British forces begin their withdrawal from Northern Persia (Iran).
|January 19, 1921
||Central American Pact of Union
||Costa Rica, Guatemala, Honduras, and Salvador agreed to establish the Federation of Central America.
|January 24-30, 1921
||The delegates focused on German reparations issues at Paris. The German government agreed to pay 11.3 billion pounds over the next 42 years, although the German government faced an acute economic crisis.
|January 26, 1921
||The Allied powers officially recognized the independence of Latvia.
||Costa Rica-Panama Border Dispute
||Panamanian forces occupied disputed territory claimed by Costa Rica.
||The Allied powers unsuccessfully attempted to end the war between Greece and Turkey in Anatolia.
|February 18, 1921
||American Withdrawal from Reparations Commission
||The Wilson administration recalled the U.S. representative from the Reparations Commission.
|February 19, 1921
||Franco-Polish Mutual Aid Treaty
||The French and Polish governments signed a defensive treaty, promising aid to the other in the event of an attack by a third party. This treaty marked the beginning of France's foreign policy to bolster Eastern Europe and develop an alliance system again
|February 21-March 4, 1921
||Twelfth League Council Session
||The League of Nations Council held its twelfth session in Paris.
|February 21-March 4, 1921
||The Allied Powers met to plan a schedule of German reparations payments and develop a plan for sanctions in the event the Germans did not maintain payment obligations.
|February 25, 1921
||Establishment of the Georgian Soviet Socialist Republic
||With the collapse of White Russian power in southern Russia, the Red Army began an offensive in the Transcaucasian region and overthrew the government in Georgia. The Bolsheviks then set up a Soviet Socialist Republic for Georgia.
|February 26, 1921
||The Bolsheviks agreed to withdraw troops from Persia (Iran), cancel all debts, abrogate the capitulations, and turn over all Russian property to Persia. The new Reza Khan government reached an agreement with the Soviet Russians and sought to undermine
|February 28, 1921
||The Russian Soviet and Afghan governments signed a treaty of friendship to improve relations between the two states. The Amanullah government worked to reduce British influence in Afghanistan.
|March 1, 1921
||Afghan-Turkish Alliance Treaty
||Afghanistan and Turkey signed a treaty of friendship and alliance, establishing a close relationship between the two countries.
|March 3, 1921
||The Polish and Romanian governments concluded an alliance designed to improve their security, primarily against Soviet Russia.
|March 8-September 1921
||French Occupation of Ruhr Cities
||French forces occupied Duesseldorf, Duisberg, and Ruhrort for six months after the German government failed to meet French reparations ultimatum.
|March 9, 1921
||Cilicia Peace Treaty
||France signed a peace treaty with Turkey, ending the fighting in
|March 10-April 20, 1921
||First General Conference of Communication and Transit
||The League of Nations hosted the First General Conference on Communications and Transit in Barcelona as the first step in improving global transportation and communication.
|March 13, 1921
||Italian Evacuation of Anatolia
||The Italian agreed to withdraw military forces in Asia Minor in return for extensive economic concessions by Turkey.
|March 15, 1921
||Cuban Presidential Elections
||In a new set of elections, brokered by U.S. General Enoch Crowder, Dr. Alfredo Zayas again won the presidency. His opponent claimed voting fraud after an earlier election in November 1920, which threatened to plunge the island into civil war.
|March 16, 1921
||The Turkish government ceded Batum to Soviet Russia in return for Soviet recognition of Turkish sovereignty over Kars and
|March 16, 1921
||Anglo-Russian Trade Agreement
||The British and Russian governments signed an agreement which established trade relations between the two countries.
|March 18, 1921
||Treaty of Riga
||Delegates of the Polish and Soviet Russian governments met and signed the Treaty of Riga, which ended Russo-Polish War of 1920 and defined eastern border of Poland
|March 20, 1921
||Upper Silesian Plebiscite
||The majority of citizens in Upper Silesia voted to remain part of Germany rather than joining Poland
||Greek Offensive in Asia Minor
||Greek forces renewed their offensive against Turks which led to the capture of
|March 24, 1921
||German Reparations Default
||The Reparations Commission declared Germany in default and subject to Allied sanctions.
|March 24, 1921
||Reparations Recovery Act
||The British government enacted the Reparations Recovery Act, imposing a 50 percent duty on German imports.
|March 27, 1921
||Failed Hapsburg Restoration
||King Karl returned to Hungary, in violation of the Treaty of Trianon, to resume power. The National Assembly voted against restoration, which forced Karl to return to exile in Switzerland.
|April 2, 1921
||Establishment of the Armenian Soviet Socialist Republic
||As a result of the Red Army offensive into the Caucasus region, the Armenian government collapsed and the Bolsheviks established the Armenian Soviet Socialist Republic.
|April 20, 1921
||The U.S. Senate ratified the Thomson-Urrutia Treaty which provided Colombia with $25 million for the American seizure of Panama (in 1903). The treaty also provided the Colombians with free access to the Panama Canal.
|April 23, 1921
||Little Entente Expanded
||The Romanian and Czechoslovak governments signed an alliance which expanded France's Eastern alliance system.
|April 24, 1921
||Austrian Tyrol voted for union with Germany, but the territory remained part of the Austrian republic as required by the terms of the World War I peace treaties (the Treaties of Versailles and St.
|April 24, 1921
||German Request for U.S. Mediation
||The U.S. government rejected the German government's request to serve as a mediator in the reparations crisis.
|April 27, 1921
||German Reparation Assessment
||The Reparations Commission announced that the German government had to pay 132 billion gold marks in total reparations.
|April 29-May 5, 1921
||The delegates at the conference demanded that the Germans pay one billion gold marks by the end of the month or the Ruhr would be occupied. To preempt an occupation, the German government borrowed the necessary funds from London and met the deadline.
|May 2, 1921
||Polish Uprising in Upper Silesia
||Adalbert Korfanty led a Polish uprising in Upper Silesia to prevent the region from returning to German sovereignty.
|May 19, 1921
||U.S. Emergency Quota Immigration Act
||The Harding administration limited immigration from individual countries to 3 percent of the number of foreign-born people of such nationality resident in the U.S. according to the 1910 census.
|May 20, 1921
||Reduction of Reparations Recovery Act
||In response to German economic problems, the British government reduced the tariff on German imports to 26 percent for reparations payments.
|May 28, 1921
||Restoration of Franco-Vatican Relations
||France resumed diplomatic relations with the Vatican (which the French government had severed in 1904).
|May 29, 1921
||Austrian Salzburg voted for union with Germany, a violation of the Versailles Treaty and the Treaty of St. Germain. The Allied governments threatened to intervene, which ended the Austrian separation movement.
|June 7, 1921
||Little Entente Completed
||The government of the Kingdom of Serbs, Croats, and Slovenes signed an alliance pact with Romania completing the Little Entente (Czechoslovakia, Romania, and the Kingdom of the Serbs, Croats, and Slovenes).
|June 17-28, 1921
||Thirteenth League Council Session
||The League of Nations Council held its thirteenth session in Geneva.
|June 22, 1921
||Afghan-Persian Non-Aggression Treaty
||Afghanistan and Persia (Iran) signed a non-aggression treaty.
|June 24, 1921
||Finnish Sovereignty over Aaland
||The League of Nations Council recognized Finnish sovereignty over the Aaland Islands over Swedish objections, although the islands were granted an autonomous government.
|June 30-July 5, 1921
||International Conference on the Treatment of Women and Children
||The League of Nations hosted a conference in Geneva that addressed a wide range of issues associated with the treatment and health of women and children.
|July 2, 1921
||Congressional Peace Resolution
||By joint resolution, the U.S. Congress passed a bill which terminated the war between the United States and Germany, Austria, and Hungary. The resolution reserved for the U.S. any rights secured by the Armistice, the Treaty of Versailles, or as a result
|July 6, 1921
||Establishment of Mongolian Socialist Republic
||The military forces of the Far Eastern Republic forced the White Russians, under Baron Ungern von Sternberg, to retreat from Outer Mongolia. The Bolsheviks established the Mongolian People's Revolutionary Government on July 6th, under Soviet Russian ausp
|July 21, 1921
||Battle of Annual
||Moroccan forces under Abdel Krim decimated a Spanish military force sent to quell the Moroccan insurrection (over 12,000 Spanish troops were killed out of a force of 20,000). The Spanish continued to suffer heavy losses while attempting to quell the Riff
|July 25, 1921
||Belgian-Luxembourg Economic Agreement
||The Luxembourg and Belgian governments signed a fifty-year economic agreement.
||Under the terms of the Treaty of St. Germain, the Austrians were to receive Burgenland, a strip of former Hungarian territory that was only 15 miles from Vienna and inhabited primarily by Germans. Hungarian irregulars refused to relinquish control and eva
||U.S. Intervention in Panama
||The U.S. government sent military forces to settle the border dispute between Panama and Costa Rica. The Americans forced the Panamanians to withdraw and allowed Costa Rican troops occupy the disputed area.
|August 22-24, 1921
||Intergovernmental Conference on Assistance to Russian Refugees
||The League of Nations hosted a conference in Geneva which addressed welfare and political issues for Russian refugees who had fled the Russian Civil War and were now destitute overseas.
|August 24-September 16, 1921
||Battle of Sakkaria
||Greek forces in Asia Minor failed to capture Ankara. This offensive marked the most westerly advance of Greek forces into Turkey.
|August 24, 1921
||U.S.-Austrian Peace Treaty
||The Harding administration signed a peace treaty with Austria, which ended First World War hostilities with the Austrians.
|August 25, 1921
||U.S.-German Peace Treaty
||The Harding administration signed a separate peace treaty with Germany.
|August 29, 1921
||U.S.-Hungarian Peace Treaty
||The Harding administration signed a peace treaty with Hungary, ending American participation in World War I.
|August 29-October 12, 1921
||Fourteenth League Council Session
||The League of Nations Council held its fourteenth (extraordinary) session in Geneva to discuss the Upper Silesia Question between Germany and Poland.
|September 5-October 5, 1921
||Second League Assembly Session
||The League of Nations Assembly held its second session in Geneva under Jonkheer van Karnebeek (The Netherlands).
|September 21, 1921
||Estonian Admission to the League
||The League of Nations admitted Estonia as a member state in the organization.
|September 22, 1921
||Latvian Admission to the League
||The League of Nations admitted Latvia as a member state in the organization.
|September 22, 1921
||Lithuanian Admission to the League
||The League of Nations admitted Lithuania as a member state in the organization.
||Persian Occupation of Gilan
||With an enlarged and modernized army, Reza Khan suppressed a revolt in Gilan and overthrew the Soviet Republic of Gilan. The Persian army successfully established control over southern Azerbaijan.
|October 10-20, 1921
||Neutralization of the Aaland Islands Conference
||The League of Nations sponsored a conference in Geneva on the issue of sovereignty over the Aaland Islands. The League awarded the islands to Finland, even though the Swedish government claimed the island and the inhabitants were Swedish. This conferenc
|October 12, 1921
||Upper Silesian Settlement
||The League of Nations settled the Upper Silesia dispute by dividing the disputed territory between Germany and Poland.
|October 13, 1921
||The French establish Niger as a separate colony.
|October 13, 1921
||Treaty of Kars
||The Turkish government formally recognized the independence of the Armenian Socialist Republic and regained Batum from the Soviet Russian government.
|October 18, 1921
||U.S. Peace Treaty Ratifications
||The U.S. Senate ratified separate peace treaties with Germany, Austria, and Hungary.
|October 20, 1921
||The French agreed to evacuate Cilicia in return for economic concessions from Turkey. In return, the Turkish government recognized French sovereignty over Syria, which helped to end hostilities in the region.
|October 20, 1921
||Aaland Islands Convention
||Through a League of Nations conference, the Finnish and Swedish governments accepted a neutralization and non-fortification agreement of Aaland Islands.
|October 20, 1921
||Attempted Hapsburg Restoration
||Former King Karl flew into Burgenland in Hungary in another attempt to resume his throne. The governments of Czechoslovakia and the Kingdom of the Serbs-Croats-Slovenes mobilized their military forces in response and forced Karl to again surrender his th
|October 24-November 21, 1921
||Third Session of the International Labor Conference
||The International Labor Organization (BIT) conducted its third session in Geneva under the chairmanship of Viscount Burnham (Britain). The delegates considered a wide range of issues including the minimum age for agricultural workers, the right of associ
|October 26, 1921
||German Acceptance of Upper Silesian Partition
||The German government accepted the League of Nations' decision to partition Upper Silesia between Germany and Poland.
|October 28, 1921
||Due to the serious economic dislocations of World War I, the Liberian government was unable to meet its foreign debt payments. A Liberian government delegation traveled to the U.S. in March 1921 to negotiate a financial aid agreement with the new Harding
|November 7, 1921
||Emperor Karl Exiled
||The Hungarians chose not to restore Karl as king and he was sent into final exile on Madeira.
|November 8, 1921
||Tunisian Nationality Law
||The French government declared that children born of foreign parents in Tunisia should be French subjects. The British government protested this decree and brought the issue before the Permanent Court of International Justice.
|November 9, 1921
||Albanian Border Settlement
||A conference of ambassadors settled the Albanian border dispute based on the 1913 demarcation, although the Kingdom of the Serbs-Croats-Slovenes received small territorial concessions in the final treaty.
|November 12, 1921-February 6, 1922
||The Harding administration called for a general conference to discuss naval disarmament and Far Eastern issues. The conference led to four major agreements including the Four-Power Pacific Treaty; the Shantung Treaty; the Nine-Power Treaties; and Naval D
|November 16-19, 1921
||Fifteenth League Council Session
||The League of Nations Council held its fifteenth session in Paris.
|November 21, 1921
||The British and Afghan governments signed an agreement which expanded the provisions of the Treaty of Rawalpindi, further reducing British influence in Afghanistan.
|November 23-26, 1921
||German-Polish Conference on Upper Silesia
||In an effort to prevent the outbreak of war between Germany and Poland over the control of Upper Silesia, the League of Nations hosted a conference between the two states in Geneva. Talks resumed in Geneva in February 1922.
||International Conference on Biological Standardization
||The League of Nations sponsored a conference in London designed to promote biological standardization to help treat infectious disease.
|December 6, 1921
||Hapsburg Exile from Hungary
||In response to political pressure from other East European countries, the Hungarian government exiled the Hapsburg dynasty in an attempt to prevent future attempts at restoring the Hungarian kingdom.
|December 7, 1921
||Irish Free State Established
||The British and Irish governments signed a peace treaty establishing the Irish Free State as a dominion within the British Empire. Under the terms of the agreement, Northern Ireland remained an integral part of the United Kingdom.
|December 10, 1921
||Delegates at the Washington Conference called for a reexamination of Chinese law and administration in regard to extraterritoriality.
|December 12, 1921
||The Persian and Turkish governments signed a treaty of peace and friendship.
|December 13, 1921
||Four-Power Pacific Treaty
||Negotiated during the Washington Conference, the British, French, Japanese, and United States governments guaranteed each parties' possessions in the Pacific. The treaty also ended the Anglo-Japanese Alliance of 1902.
|December 14, 1921
||The Italian government mediated the dispute between Austria and Hungary regarding the future of Burgenland. The two governments agreed to a plebiscite which resulted in most of the disputed territory joining the Austrian republic. The Oedenburg region,
|December 15, 1921
||Higher Australian Tariff
||The Australian government significantly increased tariffs in an attempt to protect the new industries which had been established during World War I. The government also created a Tariff Board to advise the state on tariff issues. The board eventually se
|December 21, 1921
||The Soviet and Turkish governments signed another treaty recognizing the regional status quo and extending relations between the two countries.