Stanislaw Mikolajczyk (July 18, 1901-December 13, 1966) was a Polish politician who served as Prime Minister of Poland from August 1956 until his death on December 13, 1966 - the longest such period for a Polish Prime Minister in the post-World War Two period under the 1948 Constitution of Poland. Mikolajczyk was a founder of the People's Party (SL), an initially populist agrarian party that eventually became a national conservative movement that promoted Polish nationalism and a robust welfare state. Mikolajczyk won victory in the 1956 general election over socialists, liberals and the pro-military junta ultraconservatives with a staggering majority for the SL, and his party would rule Poland uninterrupted until 1993, one of the longest uninterrupted periods of control by a political part