Zbigniew Oleśnicki or Zbigniew z Oleśnicy (December 5, 1389 – April 1, 1455), known in Latin as Sbigneus, was a high-ranking Roman Catholic clergyman and an influential Polish statesman and diplomat. He served as bishop of Kraków from 1423 until his death. He took part in the management of the country's most important affairs, initially as a royal secretary under King Vladislaus II and later as the effective regent during King Vladislaus III's minority. In 1449 he became the first cardinal of Polish origin.
At the age of twenty he was secretary to King Jagello, and fought with him in the battle of Grunwald on 14 July1410.[1] A favourite with the king, he took part in the management of the country's most important affairs. His influence with the king greatly aided him in opposing the Hussites, who had gained royal favour. On 9 July1423, he was appointed to the episcopal See of Cracow, and in 1433 he was sent by the king as legate to the council of Basle, where he endeavoured to be on friendly terms with both parties.
On 18 December1439, he was created cardinal priest with the titular church of St. Prisca, by Pope Eugene IV. As cardinal, his influence in Poland was second only to that of the king, and, during the frequent absence of Casimir IV in Lithuania, he transacted the affairs of the State. Being a man of great learning, he advanced the study of arts and letters in every possible way, and the flourishing condition of the University of Cracow during his episcopacy is due chiefly to his efforts. To repress the spread of Hussitism he called John Capistran and the Minorites to Cracow.
