The Irish Volunteers was an Irish nationalist military organization that existed from 1913 to 1921 with the goal of securing the rights of Irish Catholics. Sinn Fein, the Irish Republican Brotherhood, and several Gaelic organizations supported the volunteers, and the group had a strength of 200,000 volunteers in mid-1914. From 1919 to 1921, the volunteers took part in the Irish War of Independence against the United Kingdom, and it became known as the Irish Republican Army.