Independence in the 1920s

2 Feb 1920 — Europe:
Estonia
Treaty of Tartu
Soviet Russia recognised Estonian independence de jure and renounced 'voluntarily and forever' all sovereign rights over Estonia, ending the war and fixing the eastern border at Narva and Petseri.
Era: Independence, the War of Independence and the First Republic
Sources: Tartu Peace, 2 February 1920 · Estonian Ministry of Foreign Affairs (vm.ee), Estonia marks the anniversary of the Tartu Peace Treaty · Estonian World, Treaty of Tartu · Encyclopaedia Britannica
11 Aug 1920 — Europe:
Latvia
Latvian-Soviet Treaty of Riga
Concluding the War of Independence, Soviet Russia signed the Treaty of Riga, in which it voluntarily and irrevocably renounced all sovereign rights over the Latvian people and territory, recognising Latvia's independence.
Era: National Awakening, Independence and the First Republic
Sources: The centenary of signing the Latvia-Russia Peace Treaty to be marked in Riga · Ministry of Foreign Affairs of the Republic of Latvia, Latvia: History · Encyclopaedia Britannica
6 Dec 1921 — Europe:
Ireland
Anglo-Irish Treaty
The Treaty signed in London created the Irish Free State as a dominion within the British Empire; under its Article 12 Northern Ireland, already established by the Government of Ireland Act 1920, could opt out within a month, and a Boundary Commission would then determine the border.
Era: Rising, Independence and Partition
Sources: Irish History Timeline – From 1916 to Today · GPO Witness History Museum, Dublin, Final text of the Articles of Agreement for a Treaty, 6 December 1921 · Documents on Irish Foreign Policy, Royal Irish Academy
1921 — Asia:
Mongolia
People's Revolution captures the capital
Damdin Sükhbaatar's People's Army, with the Soviet Red Army, drives out the White Russian forces of Baron Ungern-Sternberg and takes Niislel Khüree in July 1921, installing a people's government.
Era: Independence, Revolution, and the People's Republic
Sources: Damdiny Sühbaatar · Encyclopaedia Britannica, Mongolia: Independence and revolution · Encyclopaedia Britannica
28 February 1922 — Africa:
Egypt
Declaration of Egyptian independence
After the 1919 revolution led by Saad Zaghloul and the Wafd, Britain unilaterally declares Egypt independent; Fuad I becomes king of the new Kingdom of Egypt.
Era: Ottoman Rule, Muhammad Ali and British Occupation
Sources: Egyptian revolution of 1919 · Wikipedia
6–7 Dec 1922 — Europe:
Ireland
The Free State is born; Northern Ireland opts out
The Irish Free State formally came into being on 6 December 1922; the following afternoon the Parliament of Northern Ireland decided to exercise its right under the Treaty to remain outside it.
Era: Rising, Independence and Partition
Sources: 'An end and a beginning': birth of the Irish Free State · RTÉ History, 7 December 1922: Ulster opts out of the Irish Free State · Century Ireland, RTÉ, Final text of the Articles of Agreement for a Treaty, 6 December 1921 · Documents on Irish Foreign Policy, Royal Irish Academy
24 July 1923 — Asia:
Türkiye
Treaty of Lausanne
Replacing the Treaty of Sèvres, the Lausanne treaty secured international recognition of Turkey's sovereignty and borders, the legal foundation of the modern state.
Era: World War I, the Armenian Genocide and the War of Independence
Sources: Kemal Atatürk · Encyclopædia Britannica, Ottoman Empire · Encyclopædia Britannica
20 May 1927 — Asia:
Saudi Arabia
The Treaty of Jeddah
Britain formally recognized the independence and sovereignty of Ibn Saud's Kingdom of the Hejaz and Nejd, securing its international standing.
Era: Unification and the Founding of the Kingdom (1902-1932)
Sources: Treaty of Jeddah (United Kingdom-Saudi Arabia, 1927) · Encyclopaedia Britannica, Treaty of Jeddah (1927) · Wikipedia

Treaty of Tartu

Latvian-Soviet Treaty of Riga

Anglo-Irish Treaty

People's Revolution captures the capital

Declaration of Egyptian independence

The Free State is born; Northern Ireland opts out

Treaty of Lausanne

The Treaty of Jeddah