ENNumismatics and the history of numismatics developed centuries ago in the rich collections of feudal lords and magnates. The Grand Duchy of Lithuania and the Kingdom of Poland were no exception. Among the finest collections of numismatics, books and paintings was the Radziwiłł collection located in Nieśwież. It was established by Mikołaj VI, "the Black," Radziwiłł (1515-1565). In his youth Mikołaj VI traveled throughout most of Europe and developed his passion for numismatics and such during a trip to Italy. At that time in Italy there were 380 similar collections, and Radziwiłł decided to establish the Nieśwież Collection on his estate. This article explains the importance of the Radziwiłł collection and describes its most important contents.