Jan Kazimierz Zawisza, an heir of the Zawisza-Kizgajlo clan, took an active interest in prehistory, conducting archaeological research in the basin of the River Niemen and its tributaries, and later in the caves of the Ojców Valley (near Cracow). He maintained scholarly contacts with antiquarians and other scholars from all over Europe. He also participated in archaeological and anthropological conferences, at which he delivered papers; at a conference held in Lisbon, he was awarded, by King Luiz I, with the Order of Our Lady of Immaculate Conception of Villa Viçosa. In his Warsaw residence, he regularly received many visiting foreign scholars. Zawisza offered financial support to scholarly research and publications, as well as gave aid to people exiled to Siberia and to the poor in Warsaw. He was also engaged in the construction of affordable but hygienic accommodation for workers in the city.