William Thomas Cosgrave was an Irish Fine Gael politician who served as the president of the Executive Council of the Irish Free State from 1922 to 1932, leader of the Opposition in both the Free State and Ireland from 1932 to 1944, leader of Fine Gael from 1934 to 1944, founder and leader of Fine Gael's predecessor, Cumann na nGaedheal, from 1923 to 1933, chairman of the Provisional Government from August 1922 to December 1922, the president of Dáil Éireann from September 1922 to December 1922, the minister for Finance from 1922 to 1923 and minister for Local Government from 1919 to 1922. He served as a Teachta Dála (TD) from 1921 to 1944. He was a Member of Parliament (MP) for the Kilkenny North constituency from 1918 to 1922.

Cumann na nGaedheal was a political party in the Irish Free State, which formed the government from 1923 to 1932. It was named after the original Cumann na nGaedheal organisation which merged with the Dungannon Clubs and the National Council to form Sinn Féin in 1905. In 1933 it merged with smaller groups to form the Fine Gael party.