St. Casimir (1458–1484) was a prince of Poland and Lithuania, the son of King Casimir IV, who lived amid the luxury of a royal court yet devoted himself to prayer, purity, justice and the poor, and who died of tuberculosis at twenty-five. He loved the Blessed Virgin Mary so much that a copy of the Latin hymn “Omni die dic Mariae” (“Daily, daily, sing to Mary”) was buried with him. He is the patron saint of Lithuania and of young people, especially in Poland and Lithuania. His feast day is March 4. Below are his story, the prayer of his feast and prayers to St. Casimir.
A short prayer to St. Casimir, written for this page:
St. Casimir, you were a prince who chose Christ over every earthly pleasure.
Pray for young people, that they may be pure, generous and faithful,
and help me to lift my heart above this world to the things of heaven. Amen.
Who was St. Casimir?
Casimir was born in Kraków on October 3, 1458, the third of thirteen children of King Casimir IV of Poland, Grand Duke of Lithuania, and Elizabeth of Austria. Educated by the historian Jan Długosz, he grew up prayerful and self-disciplined, often spending nights in prayer before the church doors and sleeping on the floor. At thirteen he was sent by his father with an army to claim the throne of Hungary; when the campaign failed, he returned home and refused ever to take part in such a war again.
As a young man he served for a time as regent of Poland during his father’s absence, governing with justice and concern for the poor. He refused a proposed marriage, choosing to remain celibate. He received Holy Communion often and had a deep love for the Eucharist and for Mary. Weakened by tuberculosis, he died at Grodno on March 4, 1484, and was buried in the cathedral of Vilnius, where his chapel remains a place of pilgrimage. He was canonized in the early sixteenth century.
The prayer of his feast from the 1916 daily missal:
O God, who amid the pleasures of royalty and the allurements of the world didst strengthen the holy Casimir with the virtue of constancy, by his intercession we beseech thee that the faithful may lift their thoughts above this earth, and aspire always for heavenly things. Through Jesus Christ, thy Son our Lord, who liveth and reigneth with thee in the unity of the Holy Ghost, God world without end. Amen.
What is St. Casimir the patron saint of?
- Lithuania and Poland
- Young people, especially in Lithuania
- Kings and princes
Feast day
The optional memorial of St. Casimir is March 4, the day of his death. In Lithuania it is a great feast, celebrated in Vilnius with the Kaziukas fair.
Frequently asked questions
What is St. Casimir the patron saint of?
Lithuania, Poland and young people.
What hymn is associated with St. Casimir?
“Omni die dic Mariae,” known in English as “Daily, daily, sing to Mary,” a copy of which was buried with him.
When is his feast day?
March 4.
More saints
- Patron saint of Poland
- St. Aloysius Gonzaga
- St. Stephen of Hungary
- St. Louis IX
- Catholic prayers to Mary
- Saint of the day
Texts and sources
- The Mass Every Day of the Year (1916), St. Casimir (March 4), Collect, public domain (archive.org).