In the years after the Easter Rising of 1916 in Ireland, a new independence movement had emerged, and in 1918-19 the political party Sinn Féin and its paramilitary partner, the Irish Republican Army, began a political struggle and an armed uprising against British rule. By 1922 the United Kingdom had lost a very substantial portion of its territory, as the Irish Free State came into being amid a brutal civil war. At the same time Ireland was partitioned and a new, unionist government was established in what was now Northern Ireland.
