The Red Army, composed of Russian and Belorussian forces advance in Polish territory with the intention of establishing a socialist republic. During its advance a Polish Revolutionary Committee (Tymczasowy Komitet Rewolucyjny Polski, Polrewkom) was formed by the Red Army.
In May 1920 the Polrewkom in Białystok proclaims the People's Republic of Poland. During its rule, the Polrewkom decreed a land reform, nationalization of banks, public utilities and transports, expropriations of the lands and properties of the Catholic Church. It also established revolutionaries courts that tried capitalist, German officers and citizens, and any Polish deemed counterrevolutionary or reactionary. It also started an atheist campaign and created an Anti-Catholic League.
The Battle of Warsaw lasted less then a week before Polish forces reoccupied the city and pushed back the Red Army. A Polish Red Army was created by the Polrewkom, but acted only has an auxiliary force for the Russian Red Army and had minor participation. Its main function was to keep public order and carry out the orders of the Polrewkom.
Once the Treaty of Versailles was signed and established the frontiers to the West. The Polish National Council (PRN) ordered the Polish National Army to recover the territories under rule of the Polrewkom. Having to deal with the White Forces, the revolutionary government of Russia signed a truced (August 1921) that provisionally established the borders of Belarus and Poland.
The war with socialist Russia and Belarus and downfall of Polrewkom created an anti-left coalition and sentiment in the Poland of the after-war.
The Polish Revolutionary Committee (Polrewkom) functioned has the executive and legislative power. It was assisted and guided by political commissars of the Russian Red Army. Its headquarters where established in Białystok. According to the Proclamation the Polrewkom would be dissolved and give its powers to an elected People's Supreme Council after the end of the war.
The Polrewkom, under instructions of the Russian Bolsheviks, ordered the fusion of Social Democracy of the Kingdom of Poland and Lithuania (SDKPiL) and the Polish Socialist Party-Left in the Communist Workers Party of Poland (Komunistyczna Partia Robotnicza Polski, KPRP). The KPRP would function has the only political organization in the PR of Poland. Shortly afterwards a purge was ordered to clean the party of revisionist, rightist, chauvinist and bourgeois militants.
In September 1921, the Polrewkom fled to Russia. It continued to exist for some months until it was dissolved by the Bolsheviks. The KPRP would continue to exists for some more years and purged once more of liquidist, collaborationist and leftist tendencies. Finally it was dissolved by the in 1924 And Poland Became Communist After United States Interverne