St Patrick's Day: how Ireland turned the world green

On 17 March, a Chicago river turns emerald green, crowds in leprechaun hats invade Fifth Avenue in New York, and from Dublin to Sydney a pint of dark stout topped with creamy foam is raised. A small island nation of five million people has achieved the unthinkable: turning the feast of its patron saint into a worldwide celebration. This is St Patrick's Day.

St Patrick's Day honours the patron saint of Ireland, celebrated each 17 March across the world. Originally a religious feast, it has become the great day of Irish identity, carried by an immense diaspora and an imagery of shamrocks, green and conviviality. To understand St Patrick's Day is to follow how a fifth-century missionary became the global banner of a nation.

Who was St Patrick?#

Patrick (Pádraig in Irish) lived in the fifth century and was the chief evangeliser of Ireland. Remarkably, he was not Irish: born in Roman Britain, he was captured as a teenager by raiders and taken as a slave to Ireland, where he herded flocks for six years before escaping.

Having become a priest, he chose to return to the island of his captivity to preach Christianity there. What we know of him rests partly on his own Confession, a Latin text that has come down to us and makes him one of the few direct voices of that era. His death, traditionally fixed on 17 March, became his liturgical feast — the starting point for all the rest.

Patrick was not born Irish: he was a former foreign slave who chose to return to the land of his bondage, to become, centuries later, its very face.

The shamrock and the legend of the snakes#

Two symbols dominate the imagery of St Patrick's Day. The first is the shamrock. Tradition holds that Patrick used it to explain the Christian Trinity — Father, Son and Spirit in a single three-leaved plant. True or not, the image made the shamrock the floral emblem of Ireland and the lucky charm pinned to the lapel.

The second is the legend that Patrick drove the snakes out of Ireland, casting them into the sea. Naturalists point out: Ireland never had snakes, isolated by the seas since the last ice age. The legend is therefore an allegory — the "snake" figuring the paganism the saint is said to have banished. A myth that tells less of zoology than of the island's Christianisation.

From blue to green: the colour of a nation#

It is often forgotten: the colour originally associated with St Patrick was not green, but blue — the "St Patrick's blue" still found on old insignia and flags. The shift to green takes place over the centuries, fed by Ireland's nickname, the "Emerald Isle," by the shamrock and by political movements.

Green became the colour of Irish identity, to the point that "the wearing of the green" took on a patriotic, sometimes subversive charge under British rule. Today, on 17 March, green floods everything: clothes, tinted beer, illuminated monuments. The Global Greening, initiated by Ireland, turns hundreds of sites around the world green each year, from the Tower of Pisa to the Sydney Opera House.

The festival born of the diaspora#

Paradoxically, St Patrick's Day as we know it is largely an invention of emigration. In Ireland, 17 March was long a sober religious feast, on which the pubs even closed their doors. It is across the Atlantic that the festival explodes: the first great parades take place in American cities as early as the eighteenth century, organised by soldiers and then by Irish immigrants.

The Great Famine of the nineteenth century drives millions of Irish toward the United States, where St Patrick's Day becomes an assertion of community pride in the face of rejection. Monumental parades, processions, marching bands: the festival grows with the diaspora. It is only in the twentieth century, in return, that Ireland itself reinvests 17 March as a festive and tourist showcase, with the Dublin festival.

A worldwide celebration and its ambiguities#

Today, St Patrick's Day is one of the most widely celebrated national feasts in the world, including by millions of people without the slightest drop of Irish blood. Pints of Guinness, traditional music, Irish dance, corned beef and cabbage: a festive repertoire has formed, sometimes closer to diaspora folklore than to real Ireland.

This globalisation has its flip side: some lament a festival reduced to drinking in green, far from the history of the saint and Irish culture. Others see in it, on the contrary, a formidable success of cultural influence — the soft power of a small country become, for a day, the centre of the world. To discover St Patrick's Day is to learn how a memory of exile turned into shared joy, and how English — the language of a planet-wide diaspora — also carries within it these stories of islands, migrations and belonging.

FAQ#

Why is St Patrick's Day celebrated on 17 March? Because 17 March is the traditional date of St Patrick's death, which became his liturgical feast. From a holy day it gradually became the great festival of Irish identity around the world.

Why is the shamrock the symbol of Ireland? Tradition holds that St Patrick used the shamrock to explain the Christian Trinity with its three leaves. The shamrock became the floral emblem of Ireland and a lucky charm.

Did St Patrick really drive the snakes out of Ireland? No: Ireland never had snakes, isolated by the sea since the last ice age. The legend is an allegory of Christianisation, the snake symbolising the paganism the saint is said to have banished.

Why is St Patrick's Day associated with the colour green? The original colour was blue ("St Patrick's blue"). Green took hold via the nickname "Emerald Isle," the shamrock and Irish patriotic movements, until it became the emblematic colour of the festival.

Photo credits: the images used in this article come from Pexels and Unsplash and are royalty-free.