Saint Patrick's Day is a holiday celebrated on March 17th. The day celebrates Saint Patrick who was a Christian missionary and died around 461 A.D. He was born in Britain and became the patron saint of Ireland where he preached Christianity. It is believed that he used the three-leafed shamrock plant to explain the Holy Trinity to people who were confused by it, which is why this day has become known as "The Feast of the Shamrock".
