- — Asia:
Sovietisation of Armenia
Squeezed between Turkish nationalist forces and the advancing Red Army, the First Republic fell and Armenia was Sovietised, ending its short-lived independence.
Era: Empires, the Genocide and the First Republic
Sources: Armenia — Caucasus, Soviet Union, Genocide (Modern Armenia) · Encyclopædia Britannica
- — Asia:
Azerbaijan SSR established
Following the Red Army's entry into Baku, the Azerbaijan Soviet Socialist Republic was formed, becoming a full union republic of the USSR from 1936.
Era: The Azerbaijan SSR
Sources: Azerbaijan: Russian suzerainty and the road to independence · Encyclopædia Britannica, Armenia, Azerbaijan, and Georgia: Country Studies (ed. Glenn E. Curtis) · Library of Congress, Federal Research Division
- — Europe:
The Schleswig plebiscites
Under the Treaty of Versailles, Zone 1 (Northern Schleswig) voted about 75 per cent for Denmark and Zone 2 about 80 per cent for Germany, determining where the new border would run.
Era: The Schleswig Question and the Making of the Modern Border
Sources: The reunification of Denmark in 1920 · nordics.info (Aarhus University), German-Danish War: War and the final settlement of the Schleswig-Holstein question · Encyclopaedia Britannica
- — Europe:
Aland Autonomy Act
Finland granted the Swedish-speaking Aland Islands wide-ranging cultural and political autonomy, anticipating the conditions the League of Nations would attach to its sovereignty the following year.
Era: The Aland Islands Dispute and the Interwar Republic
Sources: The special status of the Aland Islands · Ministry for Foreign Affairs of Finland, The Aland example: Autonomy protects a minority · thisisFINLAND (Finland Promotion Board)
- — Europe:
The Treaty of Trianon
Hungary lost about two-thirds of its territory and population, leaving roughly three million ethnic Hungarians outside the new borders in Romania, Czechoslovakia, Yugoslavia and elsewhere; the trauma shaped Hungarian politics for a century.
Era: Trianon and the Shrinking of Hungary
Sources: Treaty of Trianon · Encyclopaedia Britannica
- — Europe:
Government of Ireland Act: six counties
The Act created two Home Rule parliaments and defined Northern Ireland as the six counties of Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone. In March 1920 the Ulster Unionist Council had rejected a nine-county Ulster, which the 1911 census showed to be only about 56 per cent Protestant, as bringing an anti-unionist representation strong enough to endanger a northern parliament, leaving Cavan, Donegal and Monaghan to the south.
Era: Rising, Independence and Partition
Sources: Government of Ireland Act 1920 (as enacted) · legislation.gov.uk (The National Archives), Unionism divided over British plans to partition Ireland · Century Ireland, RTÉ, Ulster's Lost Counties: A Warning from the Past? (Edward Burke) · Cambridge University Press blog, A Political Count: Looking ahead to the 2021 Census (Laurence Cooley) · University of Birmingham
- — Europe:
International recognition of the union
A treaty signed in Paris by Romania, Britain, France, Italy and Japan recognized the union of Bessarabia with Romania, though the Soviet Union never accepted it.
Era: Union with Romania and the Soviet Creation of a Moldavian Republic
Sources: Union of 27 March 1918: the National Archive Agency provides access to the Sfatul Tarii collection · Moldpres (Moldova State News Agency), Moldova: History · Encyclopaedia Britannica
- — Europe:
The Svalbard (Spitsbergen) Treaty
Signed in Paris, the treaty recognised Norwegian sovereignty over Svalbard while granting all signatories equal rights to economic activity and barring warlike use; Norway took over administration in 1925.
Era: Independence, Polar Sovereignty and the Second World War
Sources: The Svalbard Treaty · Stortinget (Parliament of Norway), Svalbard · Store norske leksikon
- — Europe:
Treaty of Trianon
The Treaty of Trianon formally transferred Transylvania and part of the Banat from Hungary to Romania, stripping Hungary of about two-thirds of its territory and leaving a lasting dispute.
Era: Greater Romania: the Great War and the union of Transylvania
Sources: Treaty of Trianon · Encyclopaedia Britannica
- — Europe:
The Carinthian Plebiscite
In the disputed southern Carinthian basin, a majority of about 59 per cent voted to remain with Austria rather than join Yugoslavia, leaving a Slovene minority on the Austrian side of the border.
Era: Into Yugoslavia: War, Partition and Contested Borders
Sources: Carinthian Plebiscite, 1920 · Encyclopedia (MDPI), Slovenia since 1918 · Encyclopaedia Britannica
- — Europe:
Treaty of Rapallo and the Italian border
Under the Treaty of Rapallo, Italy gained the Slovene Littoral, the Karst and parts of Inner Carniola, subjecting a large Slovene population to Italian and later Fascist rule.
Era: Into Yugoslavia: War, Partition and Contested Borders
Sources: Slovenia since 1918 · Encyclopaedia Britannica
- — Europe:
Joining the League of Nations
Switzerland joined the new League of Nations, headquartered in Geneva, on terms that its permanent neutrality would be respected, confirming Geneva's role as a centre of international diplomacy.
Era: Neutral Switzerland: World Wars, Sovereignty and the Modern Confederation
Sources: The History of Switzerland · Federal Department of Foreign Affairs (aboutswitzerland.eda.admin.ch), Neutrality · Federal Department of Foreign Affairs (aboutswitzerland.eda.admin.ch)
- — Asia:
Treaty of Sèvres
The Allied treaty with the defeated Ottoman government proposed partitioning Anatolia among Greece, Armenia, Italy, France and others; rejected by the nationalists, it triggered the War of Independence.
Era: World War I, the Armenian Genocide and the War of Independence
Sources: Kemal Atatürk · Encyclopædia Britannica, Ottoman Empire · Encyclopædia Britannica
- — Africa:
Sobhuza II becomes Ngwenyama
Sobhuza II assumes the kingship and makes the recovery of Swazi land lost in the concessions a defining cause of his long reign.
Era: British Territory and the Road to Independence
Sources: Sobhuza II · Encyclopaedia Britannica, History of Eswatini · Wikipedia
- — Europe:
League of Nations awards Aland to Finland
The Council of the League of Nations awarded sovereignty over the Aland Islands to Finland, while obliging it to guarantee the islanders' Swedish language, culture and self-government, a landmark of peaceful conflict resolution.
Era: The Aland Islands Dispute and the Interwar Republic
Sources: The special status of the Aland Islands · Ministry for Foreign Affairs of Finland, The Aland example: Autonomy protects a minority · thisisFINLAND (Finland Promotion Board), The Aland Islands Solution: a precedent for successful international disputes settlement · United Nations Office of Legal Affairs
- — Europe:
Convention on the demilitarisation of Aland
An international convention confirmed the demilitarisation of Aland dating from the 1856 Treaty of Paris and added its neutralisation, keeping the islands outside any theatre of war.
Era: The Aland Islands Dispute and the Interwar Republic
Sources: The Legal Basis of Aland's Demilitarization and Neutralization · nordics.info (Aarhus University), The special status of the Aland Islands · Ministry for Foreign Affairs of Finland
- — Asia:
Faisal I crowned king of Iraq
Britain installs the Hashemite prince Faisal I, a leader of the wartime Arab Revolt, as king of the new Iraqi state, creating a monarchy and parliament under British supervision.
Era: Ottoman Rule, the British Mandate and the Kingdom
Sources: Faisal I — king of Iraq · Encyclopædia Britannica, Iraq — British occupation and the mandatory regime · Encyclopædia Britannica
- — Africa:
Harry Thuku founds early protest
Harry Thuku establishes the Young Kikuyu Association, one of the first organised African political movements against colonial land and labour policies.
Era: British East Africa and the Settler Colony
Sources: History of Kenya · Wikipedia
- — Europe:
Liberal constitution of 1921
Following the First World War, Liechtenstein adopted a new constitution that combined the prince with an elected Landtag and instruments of direct democracy, modernising the state as it reoriented toward Switzerland.
Era: The Turn to Switzerland, Neutrality and the Beneš Decrees
Sources: The History of the Princely House of Liechtenstein · Fürstenhaus von Liechtenstein (official Princely House), Liechtenstein: History (Alpine, Principality, Sovereignty) · Encyclopaedia Britannica
- — Oceania:
League of Nations mandate over New Guinea
Australia received a Class C League of Nations mandate to administer the former German territory as the Territory of New Guinea, governed from Rabaul and kept separate from Papua.
Era: Australian rule and the highland 'first contact'
Sources: Papua New Guinea — The colonial period · Encyclopædia Britannica, Class C mandate · Encyclopædia Britannica
- — Europe:
Universal suffrage and democracy
Sweden completed its democratic transformation, introducing universal and equal suffrage for men and women, as the Riksdag rather than the crown became the centre of political power.
Era: Neutrality, the People's Home and the Road to NATO
Sources: Decisions that have changed Sweden 1523–2023 · Sveriges Riksdag (Swedish Parliament), Sweden: The welfare state · Encyclopaedia Britannica
- — Europe:
March on Rome and Mussolini's rise to power
After the Fascist March on Rome, King Victor Emmanuel III appointed Mussolini prime minister, beginning the transition to a Fascist dictatorship.
Era: Liberal Italy, Fascism, War and the Republic
Sources: March on Rome · Encyclopaedia Britannica, Italy (Fascism, racial laws and the Second World War) · United States Holocaust Memorial Museum, Holocaust Encyclopedia
- — Europe:
Adoption of the Satversme
Latvia adopted its democratic constitution, the Satversme, in 1922, establishing the institutions of the parliamentary first republic.
Era: National Awakening, Independence and the First Republic
Sources: History of Latvia · Ministry of Foreign Affairs of the Republic of Latvia
- — Asia:
Nagorno-Karabakh autonomous oblast created
The Armenian-majority mountainous region of Nagorno-Karabakh was constituted as an autonomous oblast within Soviet Azerbaijan, freezing a contested status that would later erupt.
Era: The Azerbaijan SSR
Sources: Nagorno-Karabakh: conflicts, map and people · Encyclopædia Britannica, Armenia, Azerbaijan, and Georgia: Country Studies (ed. Glenn E. Curtis) · Library of Congress, Federal Research Division
- — Europe:
Fascist seizure of power
Amid postwar economic distress the Sammarinese Fascist Party took control in 1923 and dissolved the Grand and General Council, ruling the republic for two decades in step with Mussolini's Italy.
Era: The Arengo, Fascism and the World Wars
Sources: World wars and fascism in San Marino, 1922-1945 · SanMarinoSite, Anniversary of the Fall of Fascism and Freedom Day · Office Holidays
- — Asia:
Lausanne draws the Aegean: Articles 12 to 16
The treaty confirmed Greek sovereignty over Lemnos, Samothrace, Mytilene, Chios, Samos and Nikaria (with restrictions on fortification), kept Imbros and Tenedos Turkish, renounced the Dodecanese and Castellorizzo to Italy, and placed islands within three miles of the Anatolian coast under Turkish sovereignty.
Era: World War I, the Armenian Genocide and the War of Independence
Sources: Treaty of Lausanne, Part I Political Clauses (Arts. 6, 12-16) · BYU WWI Document Archive, The Outstanding Aegean Issues; Background Note on Aegean Dispute (Turkish position) · Republic of Türkiye Ministry of Foreign Affairs
- — Africa:
Southern Rhodesia becomes a self-governing colony
After a settler referendum, Company rule ended and Southern Rhodesia became a self-governing British colony, with land and political power reserved for the white minority.
Era: The Ndebele kingdom and British conquest
Sources: Zimbabwe: History · Encyclopaedia Britannica, History of Zimbabwe · Wikipedia
- — Asia:
Kara-Kyrgyz Autonomous Oblast created
In the Soviet national-territorial delimitation of Central Asia, the Kyrgyz lands were organized as the Kara-Kyrgyz Autonomous Oblast within the Russian SFSR, giving the Kyrgyz their own named territory for the first time.
Era: Soviet Kirghizia
Sources: Kyrgyzstan: A Country Study (in Kazakstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan: Country Studies) · U.S. Library of Congress, Federal Research Division, Kyrgyzstan: History · Encyclopaedia Britannica
- — Europe:
Creation of the Moldavian ASSR
Refusing to recognize the loss of Bessarabia, the Soviet Union established the Moldavian Autonomous Soviet Socialist Republic on the east bank of the Dniester within Soviet Ukraine, as a standing claim to the territory across the river.
Era: Union with Romania and the Soviet Creation of a Moldavian Republic
Sources: Moldova: History · Encyclopaedia Britannica, Moldavia (historical principality) · Encyclopaedia Britannica
- — South America:
Founding of the Aprista movement
Victor Raul Haya de la Torre founds the American Popular Revolutionary Alliance (APRA), a mass movement for social reform that shapes Peruvian politics for decades.
Era: The Young Republic and the War of the Pacific
Sources: Peru: History · Encyclopaedia Britannica
- — Asia:
Creation of the Tajik ASSR
In the Soviet national delimitation of Central Asia, a Tajik Autonomous Soviet Socialist Republic is established within the Uzbek SSR, with Dushanbe as its capital.
Era: Russian Conquest and the Soviet Republic
Sources: Kazakstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan: Country Studies · Federal Research Division, Library of Congress, History of Tajikistan · Encyclopædia Britannica
- — Asia:
Creation of the Turkmen SSR
In the Soviet national delimitation of Central Asia, the Transcaspian and Turkmen lands were combined to form the Turkmen Soviet Socialist Republic, with Ashgabat as its capital.
Era: Soviet Turkmenistan
Sources: Turkmenistan: A Country Study (in 'Kazakstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan: Country Studies') · Library of Congress, Federal Research Division, Turkmenistan · Encyclopædia Britannica
- — Asia:
Creation of the Uzbek SSR
The Soviet national delimitation of 1924 carves Central Asia into ethnic republics; the Uzbek Soviet Socialist Republic is created and becomes a union republic of the USSR in 1925.
Era: Russian Conquest and Soviet Rule
Sources: Uzbekistan — Russian and Soviet rule · Encyclopaedia Britannica, Uzbekistan — The Russian Conquest (Country Studies) · U.S. Library of Congress Country Studies
- — Europe:
The rise of Zog
Ahmed Zogu consolidated power, becoming president in 1925 and in 1928 proclaiming himself King Zog I, ruling an authoritarian monarchy increasingly dependent on Fascist Italy.
Era: Independence, the Conference of London and the Albanian Question
Sources: History of Albania · Encyclopaedia Britannica, Albania · Encyclopaedia Britannica
- — Asia:
Reza Khan founds the Pahlavi dynasty
Having seized power in a 1921 coup, Reza Khan deposes the last Qajar shah and is crowned Reza Shah Pahlavi, launching an authoritarian drive to modernise and centralise Iran.
Era: The Qajars, Constitutional Revolution and the Pahlavi Shahs
Sources: Pahlavi dynasty · Wikipedia, Iran — history · Encyclopaedia Britannica
- — Europe:
Boundary Commission report suppressed
After the Morning Post revealed in November 1925 that the Treaty's Boundary Commission would propose only a minor two-way transfer of territory, the British, Free State and Northern Ireland governments agreed to revoke Article 12 and confirm the existing border; the report was suppressed and published only in 1969.
Era: Rising, Independence and Partition
Sources: The Boundary Commission debacle 1925: aftermath and implications · History Ireland
- — Asia:
Accession of the second king
On Ugyen Wangchuck's death the crown passes peacefully to his son Jigme Wangchuck, confirming the stability of the new hereditary monarchy.
Era: Founding of the Wangchuck Monarchy
Sources: Nepal and Bhutan: Country Studies · Federal Research Division, Library of Congress, Bhutan — History · Encyclopaedia Britannica
- — Asia:
The Lebanese Republic and constitution
Greater Lebanon is reorganised as the Lebanese Republic with a written constitution, though France retains ultimate authority under the mandate.
Era: 1860, the Mutasarrifate and the French Mandate
Sources: History of Lebanon · Encyclopaedia Britannica
- — Africa:
Estado Novo and tightened control
The authoritarian Estado Novo regime takes shape in Portugal, hardening colonial policy and entrenching forced labour and compulsory cultivation in Mozambique.
Era: Chartered Companies and Forced Labour
Sources: Mozambique · Encyclopaedia Britannica, Chibalo · Wikipedia
- — Asia:
Sukarno founds the Indonesian National Party
Sukarno establishes the PNI, demanding full independence and giving the nationalist movement a charismatic mass leader.
Era: The Dutch East Indies and the National Awakening
Sources: Indonesia (toward independence; Japanese occupation; after Suharto) · Encyclopaedia Britannica
- — Europe:
The Royal and Parliamentary Titles Act renames the state
The Act changed the style of Parliament to 'of the United Kingdom of Great Britain and Northern Ireland' and let the Crown alter its royal style; the proclamation followed on 13 May 1927.
Era: World wars, decolonisation, and the modern UK
Sources: Royal and Parliamentary Titles Act 1927 · legislation.gov.uk (The National Archives)
- — Asia:
The Youth Pledge (Sumpah Pemuda)
Young nationalists vow to recognise one Indonesian motherland, nation and language, a foundational moment in forging a unified national identity.
Era: The Dutch East Indies and the National Awakening
Sources: Indonesian National Awakening · Wikipedia, Indonesia (toward independence; Japanese occupation; after Suharto) · Encyclopaedia Britannica
- — Europe:
The 'people's home' (folkhemmet)
Per Albin Hansson set out the vision of Sweden as a folkhemmet, a good home built on equality and mutual care, which the Social Democrats made the foundation of the modern welfare state.
Era: Neutrality, the People's Home and the Road to NATO
Sources: Sweden: The welfare state · Encyclopaedia Britannica
- — Asia:
Amanullah's reforms collapse
Sweeping modernising reforms provoke tribal and religious revolt; Amanullah Khan abdicates and flees into exile in January 1929, plunging the country briefly into civil strife.
Era: Independence, Monarchy and the Republic
Sources: Amānullāh Khan — Reformer, Monarch, Modernizer · Encyclopaedia Britannica, Afghanistan: A Country Study · Library of Congress, Federal Research Division
- — Europe:
Royal dictatorship and renaming as Yugoslavia
Amid party deadlock King Alexander suspended the constitution, imposed a royal dictatorship and renamed the state the Kingdom of Yugoslavia, deepening tensions among its nations.
Era: The Birth of Yugoslavia and the World Wars
Sources: Kingdom of Serbs, Croats and Slovenes · Encyclopaedia Britannica
- — Asia:
The Tajik SSR and the loss of Bukhara and Samarkand
The Tajik ASSR is detached from Uzbekistan and elevated to a full union republic, but the historic Persian-speaking cities of Bukhara and Samarkand are left within the Uzbek SSR.
Era: Russian Conquest and the Soviet Republic
Sources: Kazakstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan: Country Studies · Federal Research Division, Library of Congress, History of Tajikistan · Encyclopædia Britannica
- — Europe:
The Roman Question resolved
The Lateran Treaty ended the nearly sixty-year dispute over the popes' loss of Rome, reconciling the papacy to the Italian state in return for a sovereign territory.
Era: The Lateran Treaty and the Birth of Vatican City
Sources: Lateran Treaty · Encyclopaedia Britannica, Roman question · Encyclopaedia Britannica
Politics & Power in the 1920s
Every event in the Terralore archive tagged politics and power — dynasties, constitutions, revolutions and changes of regime, narrowed to the 1920s — 47 of them, drawn from 37 nations, running from 1920 to 1929. Each entry keeps the sources it was verified against and links back to the chronicle it came from.
- Events
- 47
- Nations
- 37
- Earliest
- 1920
- Latest
- 1929
- Europe
- 24
- Asia
- 17
- Africa
- 4
- Oceania
- 1
- South America
- 1
Every entry below is the same record, with the same sources, as the one on its nation’s chronicle.