Troops under General Reginald Dyer fire on an unarmed crowd in Amritsar, killing hundreds and fuelling anti-colonial sentiment.
The peace treaty ending the war between Germany and the Allies is signed in the Hall of Mirrors, imposing war guilt, territorial losses and heavy reparations on Germany.
The British government declares support for a 'national home for the Jewish people' in Palestine, while stating that the civil and religious rights of non-Jewish communities should not be prejudiced.
Irish republicans rise in Dublin and proclaim an Irish Republic; the rebellion is put down by British forces after six days.
Under the Anglo-Irish Treaty, the Irish Free State is established as a self-governing dominion of the British Commonwealth.
The Australian and New Zealand Army Corps landed on the Gallipoli peninsula in the Allies' unsuccessful campaign against the Ottoman Empire; 25 April is now commemorated as Anzac Day.
Austria-Hungary declares war on Serbia, drawing Europe's powers into a global war that lasts until the armistice of 11 November 1918.