OLESNICKI, ZBYGNIEW. – Bishop of Cracow, Polish cardinal and statesman, b. at Sienno in 1389, d. at Sandomierz on 19 April 1455.
After completing his studies at Sandomierz and Cracow, O. became secretary and favorite of King Vladislaus II Jagiello, through whose support he became Bishop of Cracow (1423) and exercised decisive influence in state affairs. O. energetically opposed the political and religious influence of the Hussites in Poland, favored an alliance with Hungary, and planned a great crusade against the Turks, led by Poland, whose military and political power would thereby extend to the Black Sea. For this reason, in 1440 O. successfully supported the candidacy of King Vladislaus III for the Hungarian throne, but the king’s death at the Battle of Varna (1444) frustrated his grand designs. Although created a cardinal by Eugenius IV in 1439, in 1441 O. accepted the cardinal’s hat and the title of legatus a latere from the antipope Felix V and, together with the other Polish bishops, sided with the Council of Basel. Only in 1449 did O. obtain confirmation of his cardinalate from Pope Nicholas V. During the reign of Casimir, O. lost his predominant position, though he continued to wield great influence in political life until his death. O. was an ambitious prelate, a bold politician, a learned humanist, but little versed in sacred science; however, he was a good administrator of his diocese, where he built numerous churches and promoted charitable works.