The international scientific conference “Borders and Identities: Social and Political Changes in Eastern Europe and the Balkans during the 20th century”, with 38 participating scientists from Serbia, Poland, Lithuania, Latvia, Ukraine, Czechia, Germany, Bulgaria, and North Macedonia, has been held at the Institute for Contemporary History. It was jointly organized by the Institute for Contemporary History and the Centre for Eastern European Studies of the University of Warsaw. At the opening of the conference, an agreement on cooperation between our institute and the Centre for Eastern European Studies was signed by the directors of the two institutions, Prof. Dr. Predrag Marković and Prof. Dr. Jan Malicki. A similar agreement was signed by Dr. Marković with Prof. Dr. Rūstis Kamuntavičius, director of the Institute of the Grand Duchy of Lithuania of the Vytautas Magnus University at Kaunas. Our associates, Dr. Dragomir Bondžić, Dr. Miomir Gatalović, Dr. Miloš.