Between 1916 and 1923 Ireland experienced a political as well as a military revolution. This book examines how—after the Easter Rising of 1916—radical revolutionaries formed a precarious coalition with (relatively) moderate politicians. The new Sinn Féin party routed its enemies, cooperated uneasily with the underground Irish government, and achieved most of its objectives before disintegrating in 1922. Its rapid collapse should not distract from its achievements—in particular its role in "democratizing" the Irish revolution—while its successors since have dominated the political life of independent Ireland.