Feast Day - March 4
St. Casimir, son of the king of Poland, was brought up from his childhood in the love of God and in learning. He tamed his youthful body by wearing a hair-shirt, and weakened it with continual fasting.
Indefatigable in contemplating the Passion of Christ, he never slackened in the spirit of prayer. He was most zealous in promoting the Catholic Faith and in doing away with the schism of the Ruthenians. So helpful and kind was he to the poor and to all those afflicted by any calamity that he earned the name of father and defender of the needy.
He preserved his virginity intact all his life. Made perfect in a short time, filled with grace and merits, he gave up his spirit to God on the day which he had foretold, in the twenty-fifth year of his age. He was famous for many miracles, and Leo X numbered him among the Saints.
Taken from The Hours of the Divine Office in English and Latin, Vol. I: Advent to Passion Sunday (Collegeville, Minnesota: The Liturgical Press, 1963), p. 1813.