Seán Lemass, Irish soldier and politician, 4th Taoiseach of Ireland (d. 1971)
Seán Francis Lemass (born John Francis Lemass; 15 July 1899 – 11 May 1971) was an Irish Fianna Fáil politician who served as Taoiseach and Leader of Fianna Fáil from 1959 to 1966. He also served as Tánaiste from 1957 to 1959, 1951 to 1954 and 1945 to 1948, Minister for Industry and Commerce from 1957 to 1959, 1951 to 1954, 1945 to 1949 and 1932 to 1939 and Minister for Supplies from 1939 to 1945. He served as a Teachta Dála (TD) from 1924 to 1969.

A veteran of the 1916 Easter Rising, the War of Independence and the Civil War, Lemass was first elected as a Sinn Féin TD for the Dublin South constituency in a by-election on 18 November 1924 and was returned at each election until the constituency was abolished in 1948 when he was re-elected for Dublin South-Central until his retirement in 1969. He was a founder-member of Fianna Fáil in 1926 and served as Minister for Industry and Commerce, Minister for Supplies and Tánaiste in successive Fianna Fáil governments.Lemass is widely regarded as the father of modern Ireland, primarily due to his efforts in facilitating industrial growth, bringing foreign direct investment into the country, and forging permanent links between Ireland and the European community. One of the most important modernizing reforms during Lemass's tenure was the introduction of free secondary education, an initiative that took effect shortly after Lemass retired as Taoiseach.