It’s become somewhat of a modern blogging tradition, around St. Patrick’s Day, for several articles to come out that attempt to shed light on various legends that have emerged over the centuries concerning the well-known patron saint of Ireland, who’s lent his name (and perhaps, according to certain folk traditions, his penchant for drink, too) to the holiday.
A particular point of fascination has been the origins of the legend of his having driven all the snakes out of Ireland—surely one of the most ubiquitous and memorable tales attached to the saint.
Although to the best of scholars’ knowledge, the historical Patrick lived sometime between the 4th and the 5th centuries, the legend of the expulsion of the snakes is a latecomer, far removed from this time: its first appearance is in the later medieval Topographia Hibernica (Topography of Ireland), written by Gerald of Wales in the 1200s. But I think it’s still worth taking a look at, to try to pinpoint the genesis of this motif—however late and ahistorical it may be.
A common theory that attempts to explain how the story came about is that it actually owes its existence to a misunderstanding, or too literal reading, of earlier tales of the saint’s expulsion of pagans from Ireland.
One article mentions a theory that it was the story of St. Patrick’s conflict with a group that venerated the Irish deity Crom Cruach—recorded in the early Irish Dindsenchas, a text relating legends associated with various Irish locales—that eventually evolved into our current tale of snakes. However, the article offers no evidence of how this happened, other than to suggest that a “botched translation” is responsible.
Another article suggests that the story originally referred to druids—a broad group that came to be associated with particular Irish religious practices—that had tattoos of snakes on their arms. Based on this, then, it’s suggested that “[a] contemporary would understand the ‘snake’ symbology for what it represented (the Druids) instead of actual serpents. When that link disappeared into the mists of time, so did the symbolic meaning of the myth.”
Yet there’s little to no evidence of any of these things. (On Patheos, Jason Pitzl-Waters has critically addressed this in his post “Saint Patrick, Druids, Snakes, and Popular Myths.”)
Although these explanations have a certain appeal in their creativity, or in terms of a kind of intuitive folk logic we might have about how stories can evolve, there’s a much more obvious route of explanation, that avoids the pitfalls here.
For example, if we were to find earlier legends of other famous figures expelling snakes from an area, this would surely give us a better lead in our quest for the St. Patrick legends under discussion here: we don’t have to resort to speculative ideas about an alteration or corruption of a story already specifically involving Patrick, but can simply suggest an appropriation of the same motif as was applied to earlier figures.
As it turns out, there are indeed multiple instances of this: exact or nearly exact analogues of the snake-banishing motif found elsewhere in European/Mediterranean traditions, popular long before even the time of the historical Patrick.
The ridding of snakes by divine or heroic figures is recorded by several ancient Greek and Latin authors, ascribed to a few different figures from mythological antiquity. For example, the 1st century BCE/CE Greek geographer and historian Strabo reproduces a fragment of Hesiod—typically dated to the 8th or 7th century BCE—in which Eurylochus, a figure known from the Homeric Odyssey, expels a monstrous snake from Salamis. Similarly, in the Fables of Hyginus, the Greek Medea—best known as the wife of Jason (of Argonauts fame)—is said to have helped free the people of a certain Absoris from a great multitude of snakes by shutting them in a tomb. Further, the Greek historian Diodorus Siculus preserves a tradition of Hercules driving out the snakes from Crete, along with other wild creatures.
In truth, there’s no telling how ancient the well-springs of this motif are. The battle of a hero with a dragon or otherwise threatening monster/creature goes back to a few millennia before the Common Era, at minimum.¹
These motifs also appear in the early biographies of Christian saints which, again, predate that of St. Patrick. There’s possibly an early variant of this in the Dialogues of Pope Gregory I, where a certain Boniface of Ferento dramatically banishes the caterpillars who have ruined his garden. Specifically in Britain, a century later Adomnán, abbot of the island of Iona, records that Saint Columba rendered the snakes of Iona powerless to hurt both humans and livestock—provided the inhabitants retain their Christian faith. Further into late antiquity, the expelling of snakes is ascribed to many other figures in Christian hagiography: St. Hilary of Poitiers in France, Julius of Novara in Italy, St. Adalbert in Silesia.²
To be sure, tales like these can become severely twisted over time. (Speaking of the Hesiod fragment mentioned earlier—vis-a-vis the druid/snake tattoo theory mentioned above—in later interpretation Eurylochus banishes a man with the nickname “Snake” from the island.³)
Yet in light of the totally unclear connection between the traditions that appear in texts like the Dindsenchas, on one hand (that is, pertaining to Patrick’s involvement in inter-faith conflict), and the traditions of medieval hagiography on the other (in which Patrick simply acts as reptilian exterminator⁴), the best theory available to us is that the banishing of the snakes motif was first popularized in Greco-Roman tradition, which was then adopted by early Christian authors who were familiar with these sources (or through an unknown mediator, now lost to history)—eventually finding their most popular host in Saint Patrick.
Throughout the Middle Ages, this tradition was “recycled,” and applied from figure or saint to another through natural processes of syncretism—a reflex of a phenomenon attested worldwide, in nearly every culture on the planet, of the transference of characteristics from deity to deity, saint to saint, and person to person.
⁂ ⁂ ⁂
 On this see Calvert Watkins, How to Kill a Dragon: Aspects of Indo-European Poetics; Ogden, Dragons, Serpents, and Slayers in the Classical and Early Christian Worlds: A Sourcebook and Drakon: Dragon Myth and Serpent Cult in the Greek and Roman Worlds.
There may be other earlier Christian sources relevant for this motif, as well—like the ~4th century Latin Acts of Philip, a Christian apocryphal text popular in antiquity, in which the apostle Philip, after being released from his imprisonment in pagan Scythian territory, expels a “huge dragon” that has been terrorizing the population. Of course, there’s a difference here in that it’s a (single) dragon, not (multiple) snakes.
Interestingly, in Herbert and McNamara’s volume Irish Biblical Apocrypha, they replicate an Irish version of this text (titled “The Passion of the Apostle Philip” there), which is “quite different” from the original (182). The relevant section of this reads
An enormous number of people in that city were suffering from various diseases as a result of the venomous emissions from that dragon. Some were made blind, others deaf or lame. And he brought upon them every other ailment also, so that they might offer sacrifices to the devil to cure those maladies, and thus their souls might be damned thereafter. The apostle Philip said to all the people in the city who were ill: “Do what I advise
, and you will be healed in body and soul. In the name of the Lord Jesus Christ, the demonic dragon who has formerly done you harm will be hunted out, and I will revive in the name of Christ those who were killed by it”. (106)
The people then assent, asking what they need to do:
“Cast out the figure of Mars, and break it”, said Philip. “In its place put the cross of Christ, and then do reverence to that”.
Here, then, we do seem to have a sort of interdependence or parallel between the “casting out” of illness (via the expulsion of the dragon) and the casting out of idols. Of course, this might also be connected with Adomnán’s tale where the snakes being “rendered . . . powerless to hurt both humans and livestock” is conditioned on their continuing faith.
However, the 8th century English historian and theologian Bede, in his Ecclesiastical History of the English People, writes of Ireland as a sort of promised land (that, for example, literally “abounds in milk and honey”) :”[n]o reptiles are found there, and no snake can live there.” This is the earliest instance of Ireland being specified as such. Further, Bede claims that “when some persons have been bitten by serpents, the scrapings of leaves of books that were brought out of Ireland, being put into water, and given them to drink, have immediately expelled the spreading poison, and assuaged the swelling.”
Finally, in the 13th century, in Jacobus De Voragine’s Golden Legend, we read that Patrick
also obtained from God that no poisonous reptile could live in the whole province; and it is said that in answer to his prayer even the woods and bark from the trees in that region effectively counteract poison.
 Though at a certain point some of these might antedate the first appearance of our tradition of Patrick and the snakes in the Topography of Gerald.
 We primarily speak of this as due to Euhemerization, though.
 See Ogden, Dragons, Serpents, and Slayers, 248.