St. Patrick was a real person and we celebrate his religious feast day and the anniversary of his death, which was in the fifth century.
The Irish have observed this day as a religious holiday for over a thousand years. On St. Patrick's Day, which falls during the Christian season of Lent, Irish families traditionally attend church in the morning and celebrate in the afternoon.
St Patrick is known as the patron saint of Ireland.
True, he was not born Irish, but he has become an integral part of the Irish heritage, through his service across Ireland in the 5th century.
Patrick was born in the later half of the 4th century AD. There are differing views about the exact year and place of his birth.