St. Patrick’s Day is one of the better known holidays around the world. With all the green around, you can’t miss it. I’m not just talking about the decorations. It seems the world has been invaded by green in the early weeks of March. The food, the clothes, the people – even the Chicago River is dyed green!

But what is St. Patrick’s Day all about?

St. Patrick’s Day, or the Feast of St. Patrick, originated in the early 17th century, became an official Christian feast, and is widely celebrated by the Catholic Church, the Anglican Communion, the Eastern Orthodox Church, the Lutheran Church and those around the world of Irish decent.

This is a day to celebrate the heritage and culture of the Irish in general, and the death of St. Patrick, recognized as the patron saint for Ireland. The wearing of green and shamrocks is in honor of St. Patrick who was said to have worn and used the shamrock to explain the Holy Trinity to the pagan Irish. The green has been associated with the Irish since as early as the 1640s –  see the use of the green harp flag by the Irish Catholic Confederation.

In the early days of this celebration, feasts were held throughout Ireland to commemorate St. Patrick. Eventually the Catholic Church placed the day on the universal liturgical calendar, and it became a holy day of obligation for the Roman Catholics.

Today, St. Patrick’s Day is celebrated in festivals around the world even by many who are not of Irish or Catholic decent. These festivals are held in myriad shades of green, with shamrocks – considered a sign of good luck – decorating everything in sight. If you’re not careful, you might get pinched for not wearing green.

So when you wake up on March 17, remember to wear green; and wherever you go, whatever you do, may the luck o’ the Irish be with you.