The LWP, Berling's Army - 1943 - 1945 

After Anders Army left the Soviet controlled territory, and it became more and more apparent that the Soviet forces were able to hold the front against the German invaders without reliance on Western aid (Lend-Lease Act) or temporary allies (like the Polish government-in-exile), the Soviets decided to assume much greater control over remaining Polish military potential in USSR (ignoring the agreements signed with the Polish government-in-exile). Increasing number of volunteers were denied the opportunity to enlist in the Polish formations, instead they have been declared Soviet citizens and assigned to the Red Army. Activities of organizations and people loyal to the Polish government-in-exile, particularly the Polish embassy in Moscow, were curtailed and its assets confiscated. Finally, diplomatic relations between Soviets and the Polish government-in-exile were severed again as news of the Katyn massacre emerged in 1943.

In 1943 the Soviet Union created in Moscow the Union of Polish Patriots (ZPP) as a communist puppet government designed to counter legitimacy of the Polish government in exile; ZPP was led by the pro-Soviet Polish communist Wanda Wasilewska.
At the same time a new army was created - the Ludowe Wojsko Polskie (Polish People's Army, LWP). Its first unit, the 1 Polish Infantry Division (1 Dywizja Piechoty im. Tadeusza Kosciuszki), was created in summer 1943, reaching operational readiness by June/July. In August, the Division was enlarged to a corps, becoming the foundation of the Polish I Corps in the Soviet Union. It would be commanded by General Zygmunt Berling; other notable commanders included General Karol Swierczewski and Col. Wlodzimierz Sokorski. The division with its supported elements was sent to the Eastern Front in September 1943; one of the most notable battles was of that period was the Battle of Lenino, the first major engagement of the Berling Army. By March 1944 the Corps was strengthened with increasing number of armor and mechanical support, and numbered over 30 000 soldiers. In mid-March 1944 the Corps was reorganized into Polish First Army. The later Soviet-created Polish army units on the Eastern Front included the the Second (1945) and the Third Polish Armies (the latter was quickly merged with the second due to recruitment problems), with total smaller formations being 10 infantry divisions (numbered from 1st to 10th) and 5 armored brigades. Plans for a Polish Front were considered but dropped, and the Polish First Army was integrated into the 1st Belorussian Front.

These units were led by the Soviet commanders, appointed by the Soviets and fought under the Soviet general command (the Second Army, for example, was led by the Soviet general Stanislav Poplavsky). In Air Force of those formations 90% of officers and engineers were Soviet ones, the situation was similar in armored formation. In the Polish Second Army they consisted 60% of officers and engineers, and in the 1st 40%. In the command staff and training the percentage of Soviets was about 70 to 85%. Special political officers, almost exclusively made up of Soviets, oversaw the Polish soldiers. The Soviets created also political military police, based on thousands of secret informants called Glówny Zarzad Informacji Wojska Polskiego in Polish.

The First Army entered Poland from the Soviet territory in 1944. Ordered so by the Soviet leadership it did not advance towards Warsaw as Germans suppressed the Warsaw Uprising fought mainly by AK (General Zygmunt Berling was relieved from command for attempts to help the uprising), and in January 1945 after Germans crushed the uprising the 1st Army participated in the Soviet Warsaw offensive that finally ended the Nazi occupation out of the ruined city. It took part in battles for Bydgoszcz, Kolobrzeg (Kolberg), Gdansk (Danzig) and Gdynia losing 20,000 people in winter 1944-45 battles. In April-May 1945 the 1st Army fought in the final capture of Berlin. The Polish Second Army fought within the Soviet 1st Ukrainian Front and took part in the Prague Offensive. In the final operations of the war the losses of the two armies of the LWP amounted to 32,000.

By the end of the war, LWP numbered about 200,000 troops. Many of the soldiers were forced into military formations from former Armia Krajowa (Home Army) units taken prisoner during Soviet advances into Poland, while others joined in order to escape labour camps, prisons and Gulags in Soviet Union.
On 21 July 1944 order of pro-Soviet Polish puppet government, the Polski Komitet Wyzwolenia Narodowego, the communist Polish resistance Armia Ludowa was integrated with Polish People's Army forming the Wojsko Polskie (Polish Army). Its first commander was General Michal Zymierski. On 8 August 1944 in one of his orders, the organizational remnants (recruitment offices, etc.) of the Polish Armed Forces in the East were dissolved.