St. Patrick’s Day is observed annually on March 17. It is a holiday celebrated around the world with large parades and parties in the center of many of the world’s largest cities. When we think of St. Patrick’s Day, we think of the color green and leprechauns. But the truth is St. Patrick’s Day is a Catholic holiday as it honors the life of a saint that has a rich history of legends and myths behind his name.

Here are five fun facts about St. Patrick and the holiday that celebrates his life.

1. St. Patrick’s Day is a religious holiday.

St. Patrick’s Day honors the patron saint and national apostle of Ireland. Although today the holiday is often associated with leprechauns, pots of gold, and parties, it started as a holiday to celebrate St. Patrick, who is credited with bringing Christianity to Ireland.

2. St. Patrick was not Irish.

St. Patrick was not born in Ireland. The patron saint was actually born in Roman Britain to a Christian family. Some sources indicate that his birth name was Maewyn Succat and that “Patricius” or “Patrick” was his adopted Christian name.

Although his father was a deacon and his grandfather was a priest, he identified as a pagan or an atheist until his teen years. At the age of 16, he was kidnapped by Irish marauders and brought to Ireland to be a slave. It was during his years in captivity as a slave that he found Christ.

After serving his master, Milchu, for six years, St. Patrick escaped and returned to Britain where he studied in a monastery for 12 years. After being appointed a bishop, St. Patrick returned to Ireland to lead people to Christ.

3. Shamrocks were used as a tool to tell people about God.

St. Patrick is believed to have used shamrocks as an evangelistic tool. Legends claim he used the three leaves of the native Irish clover to explain the Trinity (i.e., the Father, Son, and Holy Spirit). This belief led to shamrocks being part of the symbols used for St. Patrick’s Day.

4. Green was not the original color associated with St. Patrick’s Day.

Blue was the first color associated with St. Patrick, not green. In several works of art, St. Patrick is depicted wearing blue vestments. St. Patrick’s blue was also seen on ancient Irish flags and coats-of-arms.

It most likely changed colors because of the modern-day Irish flag and the green that is often associated with Ireland because of its lush countryside that has earned the country’s nickname, “Emerald Isle.”

5. The first St. Patrick’s Day parade did not take place in Ireland.

The first St. Patrick’s Day parade took place in the United States on March 17, 1762. To reconnect with their Irish roots, Irish soldiers serving in the English military marched through New York City to honor St. Patrick. Today, some of the largest St. Patrick’s Day celebrations take place in Boston and New York.