Saint Patrick was a Roman Britain-born Christian missionary and is the patron saint of Ireland along with Brigid of Kildare and Columba. When he was about sixteen he was captured by Irish raiders and taken as a slave to Ireland, where he lived for six years before escaping and returning to his family. He entered the church. He later returned to Ireland as a missionary in the north and west of the island, but little is known about the places where he worked and no link can be made between Patrick and any church. By the eighth century he had become the patron saint of Ireland. The Irish monastery system evolved after the time of Patrick and the Irish church did not develop the diocesan model that Patrick and the other early missionaries had tried to establish.
The available body of evidence does not allow the dates of Patrick’s life to be fixed with certainty, but it appears that he was active as a missionary in Ireland during the second half of the fifth century. Two letters from him survive, along with later hagiographies from the seventh century onwards. Many of these works cannot be taken as authentic traditions. Uncritical acceptance of the Annals of Ulster (see below) would imply that he lived from 378 to 461, and ministered in modern day northern Ireland from 433 onwards.