Many myths and legends surround the world's best known patron saint. But what is known about the real life of the saint they call Patrick?
Patrick was from Bannavem Taberniae, a 5th Century Roman Briton settlement. No-one knows exactly where this was, but several English, Scottish and Welsh sites lay claim including Somerset, Dumbartonshire and Holyhead.
Though his father was a deacon, and grandfather a priest, the young Patrick showed no signs of religious conviction.
Aged 16, Patrick was captured and brought to Ireland as a slave. He tended sheep on Slemish Mountain where he found God (scholars now believe he was brought to Co. Mayo, but never let truth get in the way of a good marketing opportunity).
Every St. Patrick's Day pilgrims climb 437m to the summit of this 60million-year-old volcanic plug, 48km from Belfast and signposted from the picturesque village of Broughshane, near Ballymena. The site has washroom facilities and a small display recounting the early life of St. Patrick.
Patrick escaped to Britain six years later but, after spending around 20 years in Europe, heard voices calling him back to Ireland.
This time, he arrived via the mouth of Strangford Lough and built his first church at Saul, Co. Down. Patrick died at Saul having devoting the remaining three decades of his life converting the Irish to Christianity. He is said to be buried at Downpatrick's Down Cathedral.