Complex sentence: He was born Edward Noel Kelly from Graiguenamanagh, County Kilkenny, he joined Official Sinn Féin leaving it to join the new Irish Republican Socialist Party in 1974.
Split into simpler sentences: He was born Edward Noel Kelly from Graiguenamanagh, County Kilkenny. A member of Official Sinn Féin, later on he left it to join the new Irish Republican Socialist Party in 1974.