When the Czech schools were closed by German occupants in 1939, a student – Jan Ort (1917 – 1984) – was put in the concentration camp in Sachsenhausen. Prisoner of the same camp was Juri Měrćink (1914–1988) – a student from Upper Lusatia, who was well acknowledged with his nations independence cause. Měrćink was imprisoned by the Gestapo in 1937. After the war, both of them met coincidentally during the meeting of former Sachsenhausen's prisoners in East Germany. Their common paths and interests were enough to start a long-lasting friendship. Its proof is in the letters wrote by Měrćink in Czech and Lusatian language. The author of the paper describes lives of both friends, and presents excerpts from their letters. The presented quotes concern personal and family relations, arrangements connected with visits and study visits. They also provide information on the exchange of books and magazines between both friends. Měrćink helped Ort to publish articles in Sorbian magazines, and Ort provided Czech publishers with updates on Sorbian literary activity. Their correspondence, which surely was scrutinized by East German secret police, contains interesting insights into state of affairs in East Germany and information on ever deteriorating situation of the Sorbs. The correspondence is also a proof of cultural relations’s continuity between Czech and Sorbian nations – between Hradec Králové and Bautzen.