The patron saint of Ireland, St. Patrick was born in Roman Britain. He describes his life and ministry, including his work to convert the Irish people, in his short autobiography and testimony, Confessions. Kidnapped at age 16 by Irish raiders and sold into slavery in Ireland, his time spent in captivity transformed him spiritually. He was a lonely shepherd for six years before escaping and returning home.
After returning home, his dream of converting the Irish from pagan belief propelled him to priestly studies in Gaul (now France). In about 432, Pope Celestine I consecrated him as a bishop and sent him to Ireland. For nearly 30 years, he preached tirelessly, made countless converts, founded monasteries, and established the primatial see at Armagh in modern-day Northern Ireland.
Toward the end of his life, he made a 40-day retreat on Croagh Patrick mountain in present-day County Mayo. That gave rise to the pilgrimages that are made on the mountain to this day. Stories that Patrick used the shamrock to explain the Trinity and drove snakes from the island are unconfirmed legends.