What Are the Four Cycles of Irish Mythology?

The four cycles of Irish mythology are the four broad, mostly chronological categories into which scholars like to place Irish myths.

Namely, these are the Mythological, Ulster, Fenian, and Kings’ cycles.

The Mythological cycle concerns itself with Ireland’s earliest inhabitants and conquerors. 

Here you can hear-tell of the heroics of Ireland’s divine tribe, the Tuatha Dé Danann, and how they defeated their nemesis, Balor of the Evil Eye. 

Flash forward to the Ulster cycle and the Irish gods are no longer the protagonists of the tales.

Instead, the Irish hero Cú Chulainn gets much of the narrative spotlight.

Granted, as the biological son of Lugh, Cú Chulainn is a demi-god who can hulk out on the battlefield, growing to seven feet tall.

A couple of centuries later, there’s a new hero on the block:

Fionn mac Cumhaill, or Finn McCool, leader of the roving Irish warrior society known as the Fianna.

Stories about Fionn and the Fianna—like when they chase a disguised sea-god into the Otheworld—form the basis of the Fenian cycle.

Finally, there’s the Kings’ Cycle, which is a collection of stories about mythical, semi-historical, and even some historical Irish high kings.

This cycle runs parallel to the other three cycles, while also bringing us up to the reign of the very-much-historical Irish high king Brian Boru. 

That, my friends, was the one-minute explanation of the four cycles of Irish mythology. 

So if you’re still sitting there scratching your head, don’t worry: 

I actually just came up with a really simple way to think about this…

Pssst. You can watch a video adaptation of this essay right here. Text continues below.

The Original Irish Myth Classification System: Príomh-Scéil vs. Fo-Scéil

I’m not really a big fan of the four-cycle classification system.

Because it’s not something the ancient Irish storytellers—like the Filidh, who feature in the movie Sinners—were actually using.

Instead, they divided the Irish myths into two categories:

Príomh-scéil (pronounced like preev schkale), meaning main or chief tales, and fo-scéil, meaning minor or lesser tales.

Within these two broad categories, however, there are several subcategories. 

Under the príomh-scéil banner, for example, we find cattle raids, battles, tragedies, destructions, adventures, and voyages (to name a few).

While under the fo-scéil banner we find lake-bursts, banishments, visions, and pursuits. 

An Example of a Príomh-Scéil: The Cattle-Raid (of Cooley)

An example of a príomh-scéil or chief tale is the Táin Bó Cúailnge, or Cattle Raid of Cooley, which many consider to be Irish mythology’s greatest epic. 

And while it features an extensive cast of characters, the Táin’s foremost hero is Cú Chulainn, the Hound of Culannn a.k.a. the Hound of Ulster, leader of Ulster’s Red Branch Warriors.

Much (but not all) of the Táin is set in Ulster during the reign of the legendary king Conchobhar mac Nessa, who is Cú Chulainn’s uncle.

Which means using the four-cycle system, this myth clearly falls into the Ulster cycle. Also known as the Red Branch cycle.

An Example of a Fo-Scéil: The Pursuit (of Gilla Decair and His Horse)

Now, for an example of a fo-scéil or lesser tale.

Earlier I mentioned a myth in which Fionn mac Cumhaill and his Fianna chase a disguised sea-god into the Otherworld.

That one’s a pursuit.

The Pursuit of the Gilla Decair and His Horse.

And as a story, it really couldn’t be more different from the Táin. 

The stakes. The structure. (We’ll get into it.)

The Strength of the OG Way of Classifying Irish Myths

Using the four-cycle system, we call The Pursuit of the Gilla Decair and His Horse a Fenian cycle myth; we call The Cattle Raid of Cooley an Ulster cycle myth; and at face value, they sound equal.

That’s the strength of the original Irish mythology classification system, with the two broad tiers and the branching subcategories:

It takes into account both a myth’s subject matter and the importance of that subject matter.

Cattle raids are a big deal and can have major consequences.

In the Táin Bó Cúailnge, for example, the kingdom of Connacht invades the kingdom of Ulster.

All because Connacht’s Queen Medb really wants a prized brown bull so her wealth will remain equal to her husband’s wealth.

(He owns a prized white bull.)

Ulster’s champion Cú Chulainn is able to fend off Medb’s army, essentially singlehandedly, but not before he’s forced to kill his best friend and foster brother, Ferdiad.

He also kills hundreds if not thousands of other people while his fellow Red Branch warriors are incapacitated by labor pains courtesy of a curse from the sovereignty goddess, Macha.

That is a cattle raid. 

And to be sure, my summary is barely scratching the surface. 

But the takeaway is that cattle raids are about a lot more than just stealing cattle.

They have complex plots full of family drama and personal betrayals and, in some cases, dragons.

Go read the Táin Bó Fráech (or Cattle-Raid of Fráech), which some scholars argue was the original inspiration for the Old English epic, Beowulf. 

Pursuits, on the other hand… 

…didn’t inspire Beowulf. 

Let’s look at our example. 

In The Pursuit of the Gilla Decair and His Horse (Gilla Decair meaning “troublesome servant”), fifteen of Fionn mac Cumhaill’s warriors mount a grumpy giant’s horse.

The horse runs off across the sea with the fifteen of them on its back.

Fionn is obligated to give chase and otherworldly shenanigans ensue.

Don’t get me wrong, The Pursuit of the Gilla Decair and His Horse is an awesome myth. 

Just like The Hobbit is an awesome book. 

Meanwhile, the Táin Bó Cúailnge is The Lord of the Rings.

No, that’s not a perfect analogy. 

As the Irish myth chronology hawks among you no doubt noted, it doesn’t make chronological sense for me to compare The Pursuit of the Gilla Decair and His Horse to The Hobbit and the Táin to The Lord of the Rings because in Irish mythology, the pursuit in question happens well after the events of the aforementioned cattle raid.

The One Benefit of the Four Cycles: Chronology

And that’s what the four cycles bring to the table: chronology. 

A timeline.

Like this one, that I made in my previous essay/video.

Using the four cycles is akin to classifying popular music by decade—hits of the 60s, 70s, 80s, 90s—as opposed to by genre and/or structure:

Power ballad, pop punk, polka.

No, that’s not a perfect analogy either. 

Because the location of a myth on the in-universe timeline, if you will, doesn’t actually tell us how old that myth is.

For example, some Ulster cycle stories were recorded before some Mythological cycle stories. 

Sort of like how the original Star Wars trilogy was made before the prequel trilogy even though chronologically, the latter takes place earlier. 

And this leads us to the key to understanding the four cycles of Irish mythology that I teased earlier:

The four cycles can be mapped, pretty seamlessly, to the Star Wars franchise. 

(Indulge me.)

How the Four Cycles of Irish Mythology Are Like the Star Wars Franchise

As previously stated, the Mythological cycle is the prequel trilogy.

Not only because of its chronology but also because it features a bunch of superpowered people running everything: the Jedi—I mean the Tuatha Dé Danann.

But then comes Order 66—I mean the Milesian Invasion—and those superpowered folks all get killed or exiled. 

Don’t worry, some of them will pop up again in later cycles.

Which leads us to the Ulster cycle, which is the original trilogy.

Again, not just because of chronology but in this case because the cycle contains what is often considered to be the best story of the entire catalogue: The Empire Strikes Back, I mean the Táin Bó Cúailnge.

In which our young blond male protagonist, who has been trained to use an ancient weapon, finds out his biological father is actually one of the superpowered people who used to run everything.

Yeah, so in the Ulster cycle, Cú Chulainn famously goes to the Fortress of Shadows to train with a martial arts expert so he can learn how to use the Gáe Bulg, this crazy dangerous spear with tons of barbs at the end of it.

Then, when Cú Chulainn is fending off Queen Medb’s army, Lugh, the god of many talents and chief hero of the Mythological cycle appears to him and says:

Hey, I’m your daddy.

Now, let’s move on to the Fenian cycle, which is like the Star Wars sequel trilogy.

No, not because it doesn’t stick the landing.

Or because there’s a main character named Finn.

But because it repeats a lot of the same stuff we find in the previous cycles.

A young hero, who will inevitably come into possession of a cool old weapon, proves themselves worthy by completing some feat of bravery.

For Cú Chulainn, that was killing a dog with a hurley.

For Fionn, it’s slaying a fire-breathing monster with an enchanted spear.

As for the Kings’ Cycle: 

That’s the A Star Wars Story stuff. 

The non-Skywalker Saga stuff.

Your Rogue Ones and Solos and Starfighters and what have you.

And the streaming stuff too.

Your Andors and Mandalorians and Acolytes.

Kings’ cycle stories can take place anywhere on the Irish mythology timeline.

Including in-between the other three cycles.

On the rare occasion, an OG member of the Tuatha Dé Danann might make an appearance—like when the sea-god Manannán mac Lir appears to the High King Cormac mac Airt.

But for the most part, Kings’ cycle stories deal with non-divine characters.

It’s as close to history as Irish mythology gets.

Hence, it’s also known as the Historical cycle. 

So there you have it: The four cycles of Irish mythology explained using Star Wars.

Don’t even get me started on how the first High King of the Tuatha Dé Danann, Nuada of the Silver Hand, got his hand lopped off in battle and had it replaced with a silver robot hand. 

Don’t. Even. Get me started. 

I’m gonna save that for a future essay and video. 

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Want to learn about the darker side of Irish mythology? Check out…

Samhain in Your Pocket

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Irish Monsters in Your Pocket

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Neon Druid: An Anthology of Urban Celtic Fantasy

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