Alexander of Malonne was the Bishop of Płock from 1129 to 1156, a period marked by significant political, religious, and cultural development in Mazovia. He founded and endowed two churches: the cathedral in Płock, whose chapter he reformed, and the abbey in Czerwińsk, to which he brought the Canons Regular. The list of works attributed to his patronage is extensive and notably diverse, encompassing manuscripts, sculpture, metalwork, and architecture. Moreover, this group display remarkable stylistic and formal diversity, having been produced by workshops across Europe, from the Rhineland to Lombardy. This paper will be dedicated to the artistic provenance of the works commissioned or brought to Mazovia at Alexander’s initiative and will discuss them in the context of his connections with foreign artistic centers. Ultimately, it will explore what this collection can reveal about Alexander himself and his ambitions for the Bishopric of Płock.