This article reminds of life and scientific achievements of a brilliant historian - Andrzej Wyczanski, an outstanding researcher of general history and early modern history of Poland. He started to study history in his hometown attending undergro- und courses at the Warsaw University, and even though he was formally awarded a master degree at the Jagiellonian University (1946), he continued his scientific career (he was appointed Professor in 1971)and work in Warsaw. He started wor- king for the Institute of History at the Warsaw University, then, since 1953 - for the Institute of History at PAN (Polish Academy of Sciences). In 1986 Prof. Andrzej Wyczanski was appointed PAN's Correspondent Member and in 1991 - Full Member. His share in the organization of science in the whole country was huge. In 1990-1992 he was Science Secretary of I Department of Social Sciences at PAN. In the next term of office of PAN authorities (1993-1995) Professor Wyczanski was appointed Vice President and Science Secretary. In 1974-2004 he worked for the Chair and then the Institute of History at the Branch of Warsaw University in Bialystok, now the University of Bialystok. He was a director of the Chair of History of Poland and General History of the 16th-18th centuries, a director of the Institute of History (1986-1991), and for many years (1991-2000) he was an extraordinarily fruitful chairman of this Institute's Science Council. In recognition of his merits in creating Bialystok's scientific historic environment and his actions aimed at the establishment of independent humanistic university in our city, the University of Bialystok's Senate awarded him a degree of doctor honoris causa. A. Wyczanski's scientific output comprises nearly 20 books and over 500 dissertations, articles, statements, reports and reviews systematically published in Poland and abroad. The immensity of his mental horizon connected with Profes- sor's special research passion brought about studies referring to practically most areas of social life in Old Poland. Within the synthesis of the Noble Republic of Poland's history he prepared and presented a new concept of the history of culture. He also promoted 15 doctoral dissertations and over 100 master thesis.