April 24, 1916 – April 29, 1916
Irish republicans rise in Dublin and proclaim an Irish Republic; the rebellion is put down by British forces after six days.
Britain and France secretly agree to divide the Ottoman Empire's Arab lands into post-war spheres of influence.
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.
Albert Einstein presents the field equations of general relativity to the Prussian Academy of Sciences, describing gravity as the curvature of spacetime.
The Bolshevik Red Army fights the White movement and other forces after the October Revolution; the Bolsheviks emerge victorious.
Protests and mutinies in Petrograd force Tsar Nicholas II to abdicate, ending more than three centuries of Romanov rule.
The US Congress declares war on the German Empire, bringing the United States into World War I on the Allied side.