On June 12, General Tadeusz Bór-Komorowski, Commander-in-Chief of the Home Army, ordered the preparation of a plan to seize Vilnius from German hands.

Lieutenant Colonel Aleksander Krzyżanowski, who commanded the Home Army's Vilnius District, regrouped all the region's partisan units for the assault, both from inside and outside of the city.

Operation Ostra Brama was meant to be carried out during an expected state of confusion among German units in Vilnius, faced with the impending arrival of major Soviet forces.

Poland had already lost its eastern territories to Stalin at the Tehran Conference, but none of the Polish soldiers that were going to fight in the Battle of Vilnius knew about it.

For example, on April 25, 1944, during a meeting of British Prime Minister Churchill with Zygmunt Berezowski [pl], a leading member of the Polish National Party, and General Stanisław Tatar, the deputy chief of staff of the Home Army.

"He [Berezowski] said that the Poles trusted Great Britain and her Prime Minister and counted on his staunch and firm support in ensuring Poland's real independence and the integrity of her frontiers.

Churchill answered 'in a grave,...even...gloomy, manner: "Obviously, a decision to resist, regardless of the consequences, is the privilege of every nation, and it cannot be denied even to the weakest..."".

'[5] Similar statements were received by the head of the Polish government-in-exile Stanisław Mikołajczyk during his visit to the United States in June 1944 and meeting with President Roosevelt.

[2] Meanwhile, the German positions inside Vilnius had been fortified and augmented by security and police troops as the city, an important transportation hub, was designated a fortress.

[1] The Wehrmacht forces under Generalleutnant Reiner Stahel attempted to break out, although only a small group reached the German lines.

Those Polish soldiers that successfully reached the forests were ordered to make their way to Grodno, Białystok, or disperse into the local terrain.

There, they became part of the infamous Gulag, the prisoner slave labor system then widespread in the Soviet Union, until their general release in 1947.