The Treaty was ratified 64 votes to 57 by the Sinn Féin members of the Revolutionary Dáil Éireann, splitting Sinn Féin irrevocably and leading to the Irish Civil War, a rupture that still defines the Irish political landscape almost one hundred years on.Drawing together the work of a diverse range of scholars, The Treaty addresses this vexed historical and political question for a new generation of readers in the ongoing Decade of Commemorations, to determine what caused the split and its consequences that are still felt today.