Patrick was born around 385 in Scotland, probably Kilpatrick. As a boy of fourteen he was captured during a raiding party and taken to Ireland as a slave to herd and tend sheep. Ireland at this time was a land of Druids and pagans. He learned the language and practices of the people who held him. During his captivity, he turned to God in prayer. Patrick's captivity lasted until he was twenty, when he escaped after having a dream from God in which he was told to leave Ireland by going to the coast. There he found some sailors who took him back to Britian, where he was reunited with his family.
He had another dream in which the people of Ireland were calling out to him "We beg you, holy youth, to come and walk among us once more."
He began his studies for the priesthood, was ordained a bishop, and was sent to take the Gospel to Ireland. He arrived in March 25th 433, at Slane. One legend says that he met a chieftain of one of the tribes, who tried to kill him. Patrick converted the Dichu (chieftain) after he was unable to move his arm until he became friendly to Patrick.
Patrick began preaching the Gospel throughout Ireland. He and his disciples converted thousands and began building churches all over the country. Kings, their families, and entire kingdoms converted to Christianity when hearing Patrick's message.
Patrick preached and converted all of Ireland for 40 years. He worked many miracles and wrote of his love for God in Confessions. After years of living in poverty, travelling and enduring much suffering he died on March 17th 461 where he had built the first church.
Patrick used the shamrock to explain the Trinity (Father, Son and Holy Spirit) and has been associated with him and Ireland since that time.
Patrick was a humble and gentle man who was completely devoted to God. He feared nothing, not even death, so complete was his trust in God, and of the importance of his mission.
Happy St Patrick's Day!