It is now a legal holiday (where banks, businesses and pubs close) in the Republic of Ireland, Northern Ireland, Montserrat, Newfoundland and Labrador. But it is celebrated worldwide by those of Irish descent and those who simply like all things Irish.

How did the shamrock become a symbol of St. Patrick's Day?

The shamrock is a small plant with three leaves of the clover or wood sorrel family that grows abundantly in Ireland year-round and thus is one of the first welcoming greens of spring.

Legend says that St. Patrick used the plant in his teachings of the Trinity — with a leaf to represent God, Jesus Christ and the Holy Ghost and the idea of "three-in-one."

How did the "wearing of the green" come about?

Ireland's national color was originally blue, but during years of struggle between the Irish and the English, green came to be associated with Irish patriots. During Queen Victoria's reign, when all of Ireland was part of Great Britain, her Irish regiment was forbidden to wear green or to display the shamrock on St. Patrick's Day. As Ireland struggled to gain independence, green, often represented by a shamrock, became the color of hope and an important symbol of the people.

Also important is the fact that Ireland is known as the Emerald Isle, largely because it is covered with green valleys, fields and pastures.

Who, exactly, are leprechauns?

Leprechauns are just one of the faerie folk who are said to inhabit Ireland. Leprechauns are generally depicted as old men and are the cobblers or shoemakers of the faerie world. Most tales depict them as essentially harmless, although they are ill-natured, mischievous, cunning and enjoy creating havoc.

Leprechauns are also said to be extremely wealthy. Some accounts say they are simply the bankers of the faerie world. Whether it is their own gold or not, they supposedly know where large caches of treasure are hidden, and they will reveal that secret to anyone who captures them.

If captured, they can't escape as long as their captor keeps an eye fixed on them, but the moment the eye is turned, the leprechaun can disappear. So they are liable to play tricks to get their captor to look away.

In earlier accounts, leprechauns were dressed in red, but since the beginning of the 20th century they have generally appeared in green and for that reason are a popular symbol on St. Patrick's Day.

Other inhabitants of the Irish faerie world include the grogoch, the sheerie, the pooka, the banshee and the dullahan, many of who have a more malevolent nature.

What is an Irish blessing?