OLESNICKI, ZBYGNIEW. - Bishop of Cracovia, cardinal and Polish statesman, b. at Sienno in 1389, d. at Sandomierz on 1 Apr. 1455.
Having completed his studies at Sandomierz and Cracovia, O. became secretary and favourite of King Vladislao II Jagellone, with whose support he became bishop of Cracovia (1423) and exercised a decisive influence in affairs of state. O. vigorously opposed the political and religious influence of the Hussites in Poland, promoted the alliance with Hungary, and planned a great Crusade against the Turks, led by Poland, whose military and political power would thereby have reached the Black Sea. Thus, in 1440, O. successfully supported the candidacy of King Vladislao III for the Hungarian throne, but the death of the King at the battle of Varna (1444) frustrated his grand designs. Although created cardinal by Eugenio IV in 1439, in 1441 O. accepted the cardinal's hat and the title of legatus a latere from the antipope Felice 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 Niccolò V. Under the reign of Casimiro, O. lost his predominant position, but nevertheless retained great influence in political life until his death. O. was an ambitious prelate, a bold politician, and a cultivated humanist, but little versed in the sacred sciences, though a good administrator.
