Born in Krakow, Casimir was the son of Casimir IV, king of Poland and grand duke of Lithuania, and Elizabeth of Austria. Known for his refusal to take up arms, personal piety, generosity to the poor and devotion to the Blessed Mother, he rejected the idea of marrying in favor of voluntary chastity. During a visit to Lithuania, he fell ill, died from tuberculosis at the age of 25 and was buried in the cathedral in Vilnius. Canonized in 1521, he is the patron of Poland and Lithuania.
