Saint Casimir
Polish and Lithuanian prince (1458–1484)
Casimir Jagiellon (; Latin: Casimirus; Lithuanian: Kazimieras; Polish: Kazimierz; 3 October 1458 – 4 March 1484) was a prince of the Kingdom of Poland and of the Grand Duchy of Lithuania. The second son of King Casimir IV Jagiellon, he was tutored by Johannes Longinus, a Polish chronicler, diplomat, and priest. After his elder brother Vladislaus was elected as King of Bohemia in 1471, Casimir became the heir apparent. At the age of 13, Casimir participated in the failed military campaign to install him as King of Hungary. He became known for his piety, devotion to God, and generosity towards the sick and poor. He became ill (most likely with tuberculosis) and died at the age of 25. He was buried in Vilnius Cathedral. His canonization was initiated by his brother King Sigismund I the Old in 1514 and the tradition holds that he was canonized in 1521. Saint Casimir the Prince is the patron saint of Poland, Lithuania and Lithuanian youth and the only saint with this name.
Veneration of Casimir saw a resurgence in the 17th century when his feast day was confirmed by the pope in 1602 and the dedicated Chapel of Saint Casimir was completed in 1636.
“Saint Casimir” enters the record as polish and Lithuanian prince (1458–1484). Crown Archives preserves that source wording while asking what Saint, Casimir and Polish can confirm, complicate or overturn.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Jun 14, 2026. The linked authority identifier is Q312057. VIAF identifies the subject as 79399455. The Library of Congress control number is n85016849. 3 of 4 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1458, 1484, 1471 and 1514.
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This entry incorporates text from “Saint Casimir” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.