When is St Patrick's Day 2023? Who Ireland's patron saint was and ...

People of Irish descent across the world will be celebrating their shared roots this St Patrick’s Day, as they do every year.

Celebrations sometimes involve special masses to venerate the saint, whereas some celebrations involve donning green clothes and sinking multiple pints of Guinness.

Here are some things you should know about the annual event – however you might choose to mark the day.

St Patrick’s Day falls every year on 17 March, which means this year’s commemoration comes on a Friday.

It’s a public holiday in Ireland and Northern Ireland, as well as the Caribbean island of Montserrat and the Canadian province of Newfoundland and Labrador, due to Irish emigrant influence.

The day has been celebrated since the 1700s in parts of the US, which has a long history of accepting immigrants from Ireland.

It’s not an official day off in the holiday-averse US, but the format associated with the day even in Ireland was heavily influenced by festivities in cities such as Chicago and Boston, where expats and associations parade through the streets. New York’s is the biggest on earth, with two million people lining midtown Manhattan to watch on.

In Ireland, every town usually has a parade, and the main parade in Dublin is televised live, with a million people taking part in long-weekend festivities.

Malta has a long tradition of celebrating, initiated by a regiment of Royal Dublin Fusiliers in the early 20th century, while Argentina’s unofficial parade attracts 20,000 revellers to a neighbourhood with several Irish bars in Buenos Aires.

The furthest celebrations afield, however, took place in 2011, when Irish-American astronaut Catherine Molloy played a 100-year-old Irish flute aboard the International Space Station to mark the day.

St Patrick is the patron saint of Nigeria, Puerto Rico, Boston, engineers and – most commonly in the public consciousness – Ireland. Born at the end of the fourth century in Roman Britain, he was the grandson of a priest – although was not particularly devout as a boy. His life changed at the age of 16 when he was kidnapped by raiders and taken to Ireland as a slave. He spent six years working as a shepherd and praying, developing a deeper relationship with God, until one day he was said have heard a voice.

“Look – your ship is ready,” it said, according to the account of the saint himself in his “Confession”, which tells his early life story.

Fleeing his master, he found a ship to take him back to Britain, where he returned to his family and continued to study Christianity there and in France. Then came a vision in which a horde of Irish appeared to him and said: “We appeal to you, holy servant boy, to come and walk among us.”

He headed to Ireland again, this time as a missionary. His arrival is dated to 432 AD, and marks a major moment in Irish history. He set about converting the previously pagan, druidic island to Christianity with remarkable success.

Soon after, a monastic system on the continental model appeared in Ireland, and the country became literate, writing in Latin and then in Irish using the Latin alphabet. Ireland can claim the longest unbroken written record in Europe, stretching through the European Dark Ages.

Folk stories say Patrick founded 300 churches and converted 100,000 people.

He’s generally associated with the northern half of the island, and specifically Armagh – where the most senior Catholic and Anglican bishops are based – and Downpatrick, where he is said to be buried.

The main miracle associated with St Patrick, and taught to all schoolchildren, is driving the snakes out of Ireland.

Attacked by some serpents while undergoing a 40-day fast on a hill, he drove his staff into the ground and sent them (and all other snakes in the country) into the sea.

As a result, unsurprisingly, he’s often invoked against snakes. There are no native snakes in Ireland to this day, but that could be to do with the climate and the vagaries of the Ice Age thaw.