St. Patrick’s Day is celebrated annually on March 17th. Common traditions include parades and festivals, musical gatherings called “céilí,” and the wearing of green attire or shamrocks. But what is the history behind this lucky holiday? Let’s find out.

St. Patrick’s Day commemorates the death of St. Patrick (believed to be March 17, 461), the patron saint and national apostle of Ireland, who lived during the fifth century. He was born in Roman Britain but was kidnapped and brought to Ireland at 16. He stayed there for over ten years as a slave before escaping. St. Patrick would become a priest before returning to Ireland to spread Christianity to its people.

Legend has it that St. Patrick explained the Holy Trinity using the three leaves of the Irish shamrock.

People in Ireland have observed the Roman Catholic feast day of St. Patrick since the ninth or tenth century. Interestingly, the first St. Patrick’s Day parade occurred in America, not Ireland. It was held on March 17, 1601, in a Spanish colony that is now St. Augustine, Florida. The parade was organized by the colony’s Irish vicar, Ricardo Artur.

Over a century later, on March 17, 1772, homesick Irish soldiers serving in the British military would march in New York City to honor St. Patrick. Enthusiasm for St. Patrick’s Day parades in major American cities would only grow from there.

All in all, St. Patrick’s Day is steeped in history. Today, it’s celebrated worldwide to honor Irish culture and heritage.