Patrick eventually returned to Ireland as a missionary, and a lot of people think he was the guy who first brought Christianity to the island, but that‘s not true. There apparently already were some Christians there when he got back. Patrick just did a better job of selling Jesus to the Irish pagans, and he was largely responsible for setting them on the path to the interesting brand of Catholicism they practice today.
In time, Patrick would be named a bishop, and though scholars don‘t seem to know the year of his death, somehow they‘re all dead certain that he died March 17. So when you get drunk today, know that you‘re actually celebrating the anniversary of his death, you sick bastards.