Historian of Belarusian origin who has been associated with Opole University for many years. In the past he has also taught at Stanford University, the Sorbonne and the University of London. His research is mainly devoted to the fate of the Polish minority in the USSR, including Soviet crimes against Poles. He is the author of such books as: “Powstanie warszawskie widziane z Moskwy, Zapomniane ludobójstwo”, “Polacy w państwie Stalina czy Polacy w Związku Radzieckim w latach 1921–1939”.