The partition of Ireland

Ireland's future split British politics for a decade. In 1913 the government proposed Home Rule: a devolved Irish parliament, still part of the UK, that Protestants in the north opposed by force of arms if needed. War in Europe pushed the plan aside, and Irish nationalists who refused to wait staged the Easter Rising in 1916, an uprising against British rule in Dublin that was put down and its leaders executed.

Guerrilla fighting followed until a peace treaty was signed in 1921, ending the conflict. The settlement it led to came into effect the following year: in 1922 Ireland became two countries, with counties in the north choosing to stay part of the UK while the rest became the Irish Free State, self-governing under its own parliament. The Irish Free State did not stand still after that: in 1949 it became a republic in its own right, the final formal step in the two countries' separation.