St. Patrick's Day is celebrated each year on March 17th. This day marks the accepted date in 493 CE of St. Patrick's death.
As St. Patrick is the figure most prominently associated with bringing Christianity to Ireland, St. Patrick's Day is celebrated by the Roman Catholic Church in Ireland as a solemnity and holy day of obligation. The holiday is also officially celebrated by the Church of Ireland, the Irish branch of the Anglican Communion. The day is marked with special liturgical programs and a breaking of Lenten fasts.
Few historical details are known about St. Patrick's mission to Ireland, although innumerable popular legends are associated with his work and play a major role in Irish culture. The shamrock's association with St. Patrick's Day comes from the popular myth that says St. Patrick used the three leaves of the plant to explain Catholicism's holy trinity to the Irish.
The holiday is also widely celebrated as a secular celebration of Irish culture. Cities around the world hold St. Patrick's Day parades and festivals to mark the occasion, with many people participating in the "wearing of the green." Popularized by Irish immigrant communities, festivities usually include traditional Irish food and drink such as corned beef and Guinness beer.