St. Patrick, the patron saint of Ireland, was actually born in Britain.
He grew up with no interest in Christianity -- until he was kidnapped at 16, National Geographic News reports. He was sent to Ireland for seven years and underwent a religious conversion. Even after reuniting with his family, he returned to Ireland, became a priest and focused his efforts on converting people to Christianity.
He died on March 17, 461, and centuries later was honored after the mythology surrounding his name grew, according to the article.
St. Patrick's Day was only a minor holiday in Ireland until the 1970s, National Geographic notes. It rose to prominence in America by Irish-Americans. Early on, it was a way for Irish immigrant communities to reconnect with their roots.