St. Casimir was a Polish prince born in October 1458. He became the grand duke of Lithuania in 1471. He dedicated his life to celibacy, despite pressure to marry the emperor’s daughter. St. Casimir spent much of his time in prayer and supported the poor. He also had a devotion to Mary. During his father’s absence, he reigned as king for a brief amount of time. St. Casimir is patron saint of Poland and Lithuania.