The patron saint of Poland and Lithuania, St. Casimir (1458-1483) was the second son of King Casimir IV and third in line for the Polish throne. While a youth, Casimir was educated by the great Polish scholar John Dlugosz, from whom he learned to be virtuous and devout; he also practiced many forms of penance, and dedicated himself to a life of celibacy.
In 1471 Hungarian princes became dissatisfied with their king, and sent a delegation to King Casimir, asking him to send his son to take over the country. Against the young prince's wishes, the king agreed. Casimir was sent to Hungary at the head of an army, but found that he was outnumbered by forces loyal to the Hungarian king. Accepting the advice of his officers, Casimir decided to return home without seeking battle. His father was very angry, and had Casimir imprisoned for three months. The youth, for his part, decided he would never again become involved in military affairs (and thus Casimir is considered the patron saint of conscientious objectors).
From then on Casimir devoted himself to prayer and study, though he reigned briefly as king when his father was out of the country. In 1483 he withstood intense pressure to enter into a marriage with a daughter of the Holy Roman Emperor, wishing instead to maintain his vow of celibacy. Soon after this Casimir died of tuberculosis, and was buried in the Lithuanian city of Vilna, which he had been visiting at the time of his death.
Young people, with proper guidance and encouragement, are capable of making noble and heroic decisions; St. Casimir was influenced by his tutor to shun the attractions of luxury and power and to choose a life of celibacy and penance.
Acting on Jesus' words "What profit would a man show for gaining the whole world in exchange for his soul?" (Matthew 16:26), St. Casimir spurned military glory and power and instead chose peace.