Bolesław Bierut in the context of "Titoism"

The history of Poland from 1945 to 1989 spans the period of Marxist–Leninist regime in Poland after the end of World War II. These years, while featuring general industrialization, urbanization and many improvements in the standard of living, were marred by early Stalinist repressions, social unrest, political strife and severe economic difficulties.Near the end of World War II, the advancing Soviet Red Army, along with the Polish Armed Forces in the East, pushed out the Nazi German forces from occupied Poland. In February 1945, the Yalta Conference sanctioned the formation of a provisional government of Poland from a compromise coalition, until postwar elections. Joseph Stalin, the leader of the Soviet Union, manipulated the implementation of that ruling. A practically communist-controlled Provisional Government of National Unity was formed in Warsaw by ignoring the Polish government-in-exile based in London since 1940.

During the subsequent Potsdam Conference in July–August 1945, the three major Allies ratified a massive westerly shift of Poland's borders and approved its new territory between the Oder–Neisse line and the Curzon Line. The area of Poland was reduced in comparison to its pre-World War II extent and geographically resembled that of the medieval early Piast dynasty era. Following the destruction of the Polish-Jewish population in the Holocaust, the flight and expulsion of Germans in the west, resettlement of Ukrainians in the east, and the expulsion and resettlement of Poles from the Eastern Borderlands (Kresy), Poland became for the first time in its history an ethnically homogeneous nation-state without prominent minorities. The new government solidified its political power, while the Polish United Workers' Party (PZPR) under Bolesław Bierut gained firm control over the country, which would remain an independent state within the Soviet sphere of influence. The July Constitution was promulgated on 22 July 1952 and the country officially became the Polish People's Republic (PRL).

The Polish Workers' Party (Polish: Polska Partia Robotnicza, PPR) was a communist party in Poland from 1942 to 1948. It was founded as a reconstitution of the Communist Party of Poland (KPP) and merged with the Polish Socialist Party (PPS) in 1948 to form the Polish United Workers' Party (PZPR). From the end of World War II the PPR led Poland, with the Soviet Union exercising moderate influence. During the PPR years, the centers of opposition activity were largely diminished, and a socialist system was established in the country.

Arriving from the Soviet Union, a group of Polish communists was parachuted into occupied Poland in December 1941. With Joseph Stalin's permission, in January 1942 they established the Polish Workers' Party, a new communist party. The PPR established a partisan military organization Gwardia Ludowa, later renamed Armia Ludowa. In November 1943, Władysław Gomułka became secretary (chief executive) of the Central Committee of the PPR. On 1 January 1944 the party created the State National Council (KRN), proclaimed to be a wartime parliament of Poland; the body was chaired by Bolesław Bierut. In June 1944 the Union of Polish Patriots, a rival to the PPR Polish-communist organization operating in the Soviet Union, recognized the KRN as "the true representation of the Polish nation". The PPR was initially a small party with marginal support; it grew because of its alliance with the victorious Soviet Union.

The 20th Congress of the Communist Party of the Soviet Union (Russian: XX съезд Коммунистической партии Советского Союза, romanized: XX syezd Kommunisticheskoy partii Sovetskogo Soyuza) was held during the period 14–25 February 1956. It is known especially for First Secretary Nikita Khrushchev's "Secret Speech", which denounced the personality cult and dictatorship of Joseph Stalin.

Delegates at this Congress of the Communist Party of the Soviet Union were given no warning of what to expect. Indeed, proceedings were opened by First Secretary Khruschev's call for all to stand in memory of the Communist leaders who had died since the previous Congress, in which he mentioned Stalin in the same breath as Klement Gottwald. Hints of a new direction only came out gradually over the next ten days, which left those present highly perplexed. The Polish communist leader Bolesław Bierut died in Moscow shortly after attending the 20th Congress.

Jakub Berman (23 December 1901 – 10 April 1984) was a Polish communist politician. An activist during the Second Polish Republic, in post-war communist Poland he was a member of the Politburo of the Polish Workers' Party (PPR) and then of the Polish United Workers' Party (PZPR). From 1948, he was considered the second most powerful politician in Poland after President Bolesław Bierut, until he was removed from power in 1956, following Bierut's death.

Alongside Bierut, Berman was responsible for party oversight of the Stalinist Ministry of Public Security, commonly known as the "UB". Under Berman's leadership, 200,000 people were imprisoned for alleged political crimes, and 6,000 were executed.

Władysław Gomułka (Polish: [vwaˈdɨswav ɡɔˈmuwka] ; 6 February 1905 – 1 September 1982) was a Polish Communist politician. He was the de facto leader of post-war Poland from 1947 until 1948, and again from 1956 to 1970.

Gomułka was born in 1905 in Galicia. A plumber from the age of fourteen, he joined the revolutionary movement, made propaganda in the trade unions and suffered the rigours of the Witos government, then of the Pilsudski dictatorship. When Nazi Germany invaded Poland in 1939, he was imprisoned in Lwow, but was later released. He moved to Warsaw and became one of the most energetic organisers of the resistance against the Nazis. In 1943, he became the leader of the left-wing resistance fighters, the general secretary of the underground workers' party. When Poland was occupied by the Red Army, he collaborated with the Lublin government, formed by the Soviets with the Polish Bierut group, which received Stalin's blessing.