[REVIEW]: Jan Biskupiec, Tractatus contra sacra concilia, ed. by W. Zega, M. Zdanek, trans. by S. Sneddon, Folia Jagiellonica. Fontes, 26, Societas Vistulana, Cracow 2024, pp. LII + 118

Volume 26 of the Folia Jagiellonica. Fontes series features a critical edition of a treatise by the Dominican and Bishop of Chełm, Jan Biskupiec of Opatowiec (d. 1452), concerning the deposition of Pope Eugene IV by the Council of Basel. The edition, long awaited by scholars, was prepared by two Cracow medievalists, Włodzimierz Zega and Maciej Zdanek. The publication of a primary source, previously known only through a few summaries, deserves particular recognition. The publication, prepared with great care, has made available an important source for the study of fifteenth-century ecclesiology. There is no doubt that this important witness to the influence of late medieval thought on the Church will attract scholarly attention and become the subject of further analysis and in-depth study.