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Saint Patrick is the patron saint of Ireland. He founded churches and planted the Catholic faith in west and north Ireland.

According to tradition, St. Patrick chased Ireland's snakes into the sea.

PHOTOGRAPH BY CORBIS

James Owen

for National Geographic

Updated March 15, 2014

St. Patrick's Day, which is celebrated worldwide on March 17, honors St. Patrick, the Christian missionary who supposedly rid Ireland of snakes during the fifth century A.D.

According to legend, the patron saint of Ireland chased the slithering reptiles into the sea after they began attacking him during a 40-day fast he undertook on top of a hill. (Related: "St. Patrick's Day: Facts, Myths, and Traditions.")

It's admittedly an unlikely tale. Ireland is one of only a handful of places worldwide—including New Zealand, Iceland, Greenland, and Antarctica—that Indiana Jones and other snake-averse humans can visit without fear.

But snakes were certainly not chased out of Ireland by St. Patrick, who had nothing to do with Ireland's snake-free status, Nigel Monaghan, keeper of natural history at the National Museum of Ireland in Dublin, told National Geographic.

Monaghan, who has trawled through vast collections of fossil and other records of Irish animals, has found no evidence of snakes ever existing in Ireland.

"At no time has there ever been any suggestion of snakes in Ireland. [There was] nothing for St. Patrick to banish," Monaghan said. (Read about the top ten St. Patrick's Day celebrations.)

So what did happen?

Snakes likely couldn't reach Ireland. Most scientists point to the most recent Ice Age, which kept the island too cold for reptiles until it ended 10,000 years ago. After the Ice Age, surrounding seas may have kept snakes from colonizing the Emerald Isle.

No Leg to Stand On

Once the ice caps and woolly mammoths retreated northward, snakes returned to northern and western Europe, spreading as far as the Arctic Circle.

But snakes have not existed in Ireland for thousands of years. Britain, which had a land bridge to mainland Europe until about 6,500 years ago, was colonized by three snake species: the venomous adder, the grass snake, and the smooth snake.

But Ireland's land link to Britain was cut some 2,000 years earlier by seas swollen by the melting glaciers, Monaghan noted.

Animals that reached Ireland before the sea became an impassable barrier included brown bears, wild boars, and lynx—but "snakes never made it," he said.

"Snake populations are slow to colonize new areas," Monaghan added.

Mark Ryan, director of the Louisiana Poison Center at the Louisiana State University Health Sciences Center in Shreveport, said in 2008 that the timing wasn't right for the sensitive, cold-blooded reptiles to expand their range.

"There are no snakes in Ireland for the simple reason they couldn't get there because the climate wasn't favorable for them to be there," he said.

Other reptiles didn't make it either, except for one: the common or viviparous lizard. Ireland's only native reptile, the species must have arrived within the last 10,000 years, according to Monaghan.

Pagans: The Metaphorical Snakes

So unless St. Patrick couldn't tell a snake from a lizard, where does the legend come from?

Scholars suggest the tale is allegorical. Serpents are symbols of evil in the Judeo-Christian tradition—the Bible, for example, portrays a snake as the hissing agent of Adam and Eve's fall from grace. (How much do you know about St. Patrick's Day? Take our quiz.)

The animals were also linked to heathen practices—so St. Patrick's dramatic act of snake eradication can be seen as a metaphor for his Christianizing influence.

"Fake" Snake

Anyone in Ireland looking for serpents to exile would probably have to settle for the slow worm, a non-native species of legless lizard that is often mistaken for a small snake. (Also see "Blind, Legless Lizard Discovered—New Species.")

First recorded in the early 1970s, the species is thought to have been deliberately introduced in western Ireland in the 1960s, according to Ireland's National Parks and Wildlife Service.

However, the reptile doesn't appear to have spread beyond a wildlife-rich limestone region in County Clare known as the Burren.

Snakes on an Irish Plain?

In the future, genuine Irish snakes are a possibility, Monaghan said.

Pet snakes deliberately released by their owners would be the most likely source, though they wouldn't be welcome.

"No alien species is without risk to well-established fauna," Monaghan explained. "The isolated nature of an island population makes Ireland highly vulnerable to any introduction, no matter how well-meaning or misguided."

Henry Kacprzyk, curator of reptiles at the Pittsburgh Zoo & PPQ Aquarium, said in 2008 that Ireland's indigenous wildlife would not be prepared for snake introductions. (See National Geographic's Ireland pictures.)

Invasive snakes such as the brown tree snake have already wreaked havoc in Guam and other island ecosystems, he added.

Nor would getting rid of any such unwanted creatures be as easy as St. Patrick made it look.

"I don't want to completely burst the celebratory myth of St. Patrick," Kacprzyk said. "I want to keep some of it alive."

20 comments
g m
g m

Most of you probably never heard of the "Twa". The Twa are a pygmy {small race of people} tribe from Africa that has a history that pre-dates the story of Adam & Eve by almost 8500 years. T...he Twa journeyed to Northern Ireland very early in it's conception prior to the influence of the Roman Catholic Church & had a cultural, technological, & philosophical impact on a people there known as the Druids. One of the cultural influences the Druids got from the Twa was the fact that they wore a fez or head cover that depicted the African symbol known is a Uraeus, which is the same snake image you see worn by the Kings & Queens in ancient Kemet {Egypt}.
Now, the Roman Catholic Church seeing the practices of the Druids wanted to convert them, and if they couldn't, the would remove them & their beliefs as well along with the Twa who were still present in Northern Ireland at that time. This guy now known as ST PATRICK was given an order to set up Roman Catholic Churches all over Northern Ireland, and in the process, convert or remove the Druid & Twa influence. Guess which one Mr. Patrick carried out??????? He killed countless numbers of Druids & the Twa in the name of Father, the Son, & the Holy spirit.
So when you hear people tell you that he was made a saint because he removed the snakes from Northern Ireland, it's really referring to the Uraeus head garment worn by the Druids & the Twa. And the leprechaun myth comes from the short Black men that were murdered all in the name of religion. 

Jason Best
Jason Best

He wasn't referring literally to snakes, he was figuratively speaking.  St Patrick was referring to the non-believers as 'snakes', it was also a reference to the serpent in the garden of Eden.  St Patrick saw Ireland as a potential garden of Eden.

Charlie McCarthy
Charlie McCarthy

I tried to take your quiz... I answered the very first question by saying St. Patrick came from Scotland, as he did, he was captured as a boy and taken into slavery in Ireland, gained his freedom and returned to Ireland to preach Christianity, even though he wasn't the first to do so!!??

Im afraid your answer of stating that he came from Ireland, has me wondering what other nonsense, I may have been told from National Graphic. Its just plain lazy journalism. Ill tell my pupils to regard all 'evidence' from your organisation with the same suspicion that we teach them to have with Wiki.

Shame on all lazy journalism!!!   

Robert Hersh-Geer
Robert Hersh-Geer

Typical Christian religious myths....if they dont know how it happened, make up a story about it and say its Gods will.

Mike Childers
Mike Childers

I would be nice if a few of you scientific knuckleheads would spend less time writing articles about the unimportant, and spend more time inventing stuff that relieves some suffering in this world.

Joey Meatballs Gumba
Joey Meatballs Gumba

Snakes pertain to Evil.....as he spread the word to the Pagan's  while using the 3 leaf clover to represent the Trinity....... It was a Metaphor 

gary granville
gary granville

Strange that the obvious explanation of the "miracle" has escaped commentary!

Patrick's fasting and the insomnia that can accompany it most probably produced halucinations (from endogenous DMT for example) of the type that are provided by Ayahuasca; snakes everywhere. As the halucinations faded, he would have attributed the banashing of the snakes to his spiritual combat. The un-educated flocks with whom he shared his experience had no reason to doubt the veracity of his adventure, which to him was very real indeed. And so a legend was born...

Bill Morgan
Bill Morgan

Did Batman drive away the inmates of Arkham asylum to save Gotham city?

Did Luke Skywalker drive away the Empire guided by the dark side of the force save the rebel alliance?

Did Superman drive away the sociopathic Lex Luther to save Metropolis?


You debate the metaphors for what is good and evil.  Debating the existence of the dark side of the force is ridiculous (albeit fun).   I find your lack of faith disturbing!

BURMAN misenar
BURMAN misenar

........another religious "belief " ,  Yea!! Science Rules---AGAIN

Carter Fox Jr.
Carter Fox Jr.

There are no snakes on Bermuda, you missed that one.

Terry Ebert
Terry Ebert

Wake up non-believers... Saints make miracles, St. Patrick ridded Ireland of snakes so stop pretending that science proves otherwise. 

Richard Columbare
Richard Columbare

As long as we celebrate St.Patricks day by drinking green beer and eating corned beef and cabbage,then St.Patricks day is among my favorite holidays.   

Rin Rife
Rin Rife

@Mike Childers  James Owen was a journalist, and is a freelance writer and author, not a "scientific knucklehead". He's doing precisely what his job is.

Knucklehead.

Rin Rife
Rin Rife

@Joey Meatballs Gumba  Except that the pagans weren't evil, merely different, which makes the metaphor an example of the evils of large scale conversion without regard to the people you are converting, and basing "heroic" tales on metaphors that would make others evil for merely -being- different.

John Gunnett
John Gunnett

@BURMAN misenar  

Religious "beliefs " are so amusing. The fact that people believe them over science or just plain logic overwhelms me.

Andrew Howley
Andrew Howley expert

@Rin Rife @Joey Meatballs Gumba  Pagans weren't out-and-out evil in all they did, but they weren't just "different" -- there's no getting around the Celtic practice of human sacrifice. There's good reason people wanted to change things.  


There was also no major military or governmental invasion forcing the spread of early Christianity in Ireland. It was adopted by people who found something they liked in it.


Also, the amount of continued cultural traditions and art in Ireland makes it not an example of the evils of large scale conversion (of which there are plenty around the world, religious as well as secular), but an example of how people can adopt new values and practices freely and express them in a way authentic to their own culture.


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