The day commemorates Saint Patrick and the arrival of Christianity in Ireland, and, by extension, celebrates the heritage and culture of the Irish in general. Saint Patrick's Day was made an official Christian feast day in the early 17th century and is observed by the Catholic Church, the Anglican Communion (especially the Church of Ireland), the Eastern Orthodox Church, and the Lutheran Church. 461), the foremost patron saint of Ireland. Saint Patrick's Day, or the Feast of Saint Patrick ( Irish: Lá Fhéile Pádraig, lit.'the Day of the Festival of Patrick'), is a religious and cultural holiday held on 17 March, the traditional death date of Saint Patrick ( c. Christian processions attending Mass or service