ENThe problems of eastern (south-eastern) Lithuania in the mid-20th century were complex and broad in scope. As a result, historical research is divided into many areas. This is especially true regarding the period between 1939 and 1944. However, the origins of the wartime events lie in the 1920s, when Gen. Lucjan Żeligowski, acting under orders from Poland s Lithuanian-born leader Juzef Piłsudski, seemingly rebelled and mounted a deceitful attack against the young Republic of Lithuania, against the terms of the newly-signed Treaty of Suwałki. This brief report therefore focuses only on certain aspects of these events and related issues. From 1920 until 1939, in the occupied and annexed part of Lithuania, Poland carried out an intensive forced polonisation of the local population. This process has been described in the conclusions of a special commission, established by the Lithuanian Government in 1993 to investigate the activities of Poland’s Armia Krajowa (English: ‘Home Army’) in Lithuania. During 1943 and 1944, the leadership of Armia Krajowa units that operated in the eastern (south-eastern) Lithuania, like the London-based Polish government in exile, did not recognise the legality of the 1939 transfer of Vilnius and a part of the eastern Lithuanian territory to Lithuania, and sought to rebuild the Polish state within the borders that existed before the beginning of World War II.For this reason, the actions of Armia Krajowa partisans were directed not only against the Nazis and Bolsheviks (against the Soviet partisans), but also bore an anti-Lithuanian character. They were directed against personnel of Lithuanian administration, teachers and forestry workers. Lithuanians were terrorised and even killed. Units of Armia Krajova active in the Vilnius region liaised with the Nazis to receive weapons, ammunition and other military resources, as well as to gain information about Lithuanian military units formed and led by General Povilas Plechavičius. In July 1944, when the East Front and the Soviet Army approached Vilnius, Armia Krajowa attempted to occupy the city - a move that was not favoured by the geopolitical situation in Central and Eastern Europe, after agreements struck between the Soviet Union, United States and Britain. The Poles’ symbolic act was unsuccessful. After an internment camp was established in the medieval castle of Medininkai, the town’s history became inextricably linked to the disarmament and internment of the Armia Krajowa forces operating in Lithuania.