Irish political party. Its main aim was to create a united republican Ireland, politically and economically independent of Britain. Eamon de Valera founded the Party in 1926 from opponents of the Anglo-Irish Treaty (1921), which established the Irish Free State. The Party won control of the government (1932). It dominated Irish politics for the following decades, being out of office only for short periods. In 1973 it lost to an alliance of the Fine Gael and the Labour Party, but returned to government in 1977 and has held power, either alone or in coalition, for most of the years since then (1977–81, 1982, 1987–94, and 1997–2011).