Patrick is the Patron Saint of Ireland. He was a slave there who escaped, only to return as a Christian missionary, reputed to have baptized hundreds of people. It obviously stuck.
I saw a man coming, as it were from Ireland. His name was Victoricus, and he carried many letters, and he gave me one of them. I read the heading: "The Voice of the Irish". As I began the letter, I imagined in that moment that I heard the voice of those very people who were near the wood of Foclut, which is beside the western sea—and they cried out, as with one voice: "We appeal to you, holy servant boy, to come and walk among us."