This article presents the life and work of Marian Morelowski (1884–1963), an outstanding Polish art historian. He was born at Wadowice (1884), studied French in Cracow, Vienna and Paris (1902–1907) and took his doctorate in 1912. Morelowski worked as an expert on the regaining of Polish cultural heritage from Russia and the Soviet Union (1915–1926) and as a curator in the Royal Castle in Cracow (1926–1929). In 1930 he moved to Vilnius and was awarded the post of Professor of Art History at the local university. After World War II had finished, he continued his academic career in Lublin (1945–1948) and Wroclaw (1948–1960), where he died in 1963. Morelowski’s main fields of research were the artistic relations between Poland and the Meuse region in the Middle Ages, the art of the Vilnius region and medieval and early modern art in Silesia. Morelowski treated his work as an undertaking dedicated to the service of Polish national culture. His research work strictly adhered to the nationalist ideology of the independent Polish state and was opposed to the views of German art historians.