After the German conquest of Poland, a Polish government-in-exile was formed under the protection of France and Britain. The President of the Republic and the government-in-exile were recognized by the United Kingdom and, later, by the United States until 6 July 1945, when the Western Allies accepted the Communist-led government backed by Stalin. Despite having lost recognition by other governments, the government-in-exile continued in London until the election of Lech Wałęsa as President of the Republic of Poland in December 1990 - when it handed over its formal powers and the insignia of the Polish Second Republic to President-elect Walesa in a ceremony at the Warsaw Royal Castle on 22 December 1990.
The sole internationally recognized President of the exiled government was Władysław Raczkiewicz, who took office after Ignacy Mościcki's resignation in September 1939.
The People's Republic of Poland was founded under Soviet protection on 31 December 1944 and recognized by the United States and the United Kingdom since 6 July 1945.
In 1952, the July Constitution abolished the office of president and made the Council of State the collective head of state, chairmen of which are listed below. Real power rested with the Polish United Workers' Party (PZPR), its Central Committee and its secretary general/first secretary.
From 1954 the head of the party was also the Chairman of the Central Committee: