On March 17 each year, millions of people pay homage to St. Patrick, the patron saint of Ireland, with parades, parties and religious services.

Although St. Patrick’s Day has evolved into a festivity filled with fun, the day was once a religious feast day honoring the man many credit with bringing Christianity to Ireland.

He xqspent many years evangelizing in the northern half of Ireland and converted thousands of people from paganism to Christianity. According to legend, St. Patrick used the three-leaf clover to explain the Holy Trinity to the Irish. Patrick’s efforts to drive out the pagans became an allegory in which he drove “snakes” out of Ireland.