Saint Patrick was a 5th-century Romano-British Christian missionary and Bishop in Ireland. Much of what is known about Saint Patrick comes from the Declaration, which was allegedly written by Patrick himself.
Today's Saint Patrick's Day celebrations have been greatly influenced by those that developed among the Irish diaspora, especially in North America. Until the late 20th century, Saint Patrick's Day was often a bigger celebration among the diaspora than it was in Ireland.
A leprechaun is a type of fairy of the Aos Sí in Irish folklore. They are usually depicted as little bearded men, wearing a coat and hat, who partake in mischief. They are solitary creatures who spend their time making and mending shoes and have a hidden pot of gold at the end of the rainbow.
A pot of gold at the end of the rainbow - a pot full of St. Patrick's Day wishes.