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Aos Sí – Ancestors of Ireland

Irish mythology is full of creatures and beings, many of which are unique. One such category of beings is the Aos Sí. Considered to be the ancestors of the Celts, the Aos Sí are complex beings, depicted in various ways.

Who are the Aos Sí?

The Aos Sí are an ancient elf-like or fairy-like race of beings that are said to still live in Ireland, hidden from human sight in their underground kingdoms. They are treated with respect and appeased with offerings.

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Although these beings are typically depicted as halflings, or tiny fairies, in modern movies and books, in most Irish sources they were said to be at least as tall as humans tall and fair. They are said to be very beautiful.

Depending on which myth you read, the Aos Sí are said to either live in the many hills and mounds of Ireland or in a whole different dimension – a parallel universe that’s similar to ours but populated with these magical creatures instead of people like us.

In either interpretation, however, it’s clear that there are pathways between the two realms. According to the Irish, the Aos Sí can often be seen in Ireland, whether it’s to help us, to sow mischief, or just to mind their own business. 

Are The Aos Sí Fairies, Humans, Elves, Angels, Or Gods?

Riders of the sidhe
Riders of the Sidhe by John Duncan (1911). Public Domain.

The Aos Sí can be seen as many different things. Various authors have depicted them as fairies, elves, gods or demi-gods, as well as fallen angels. The fairy interpretation is indeed the most popular. However, the Irish version of fairies doesn’t always correspond with our general idea of fairies.

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Even though some types of Irish fairies like the leprechauns were portrayed as small in stature, most Aos Sí were as tall as people. They had distinct elfish features such as long fair hair and tall, slender bodies. Additionally, there are many types of Aos Sí, some of which were rather monstrous.

Here’s a brief look at the possible origins of these beings.

Mythological Origins

There are two main theories in Irish mythology regarding the origin of the Aos Sí.

According to one interpretation, the Aos Sí are fallen angels – heavenly beings of divine origins that lost their divinity and were cast down to Earth. Whatever their transgressions were, they clearly weren’t enough to earn them a place in Hell, but were enough to get them cast out of Heaven.

Obviously, this is a Christianized view. So, what is the original Celtic understanding of their origins?

According to most sources, the Aos Sí are the descendants of the Tuatha Dé Danann (or the People of the Goddess Danu). These were viewed as the original divine inhabitants of Ireland before the Celts (the mortal Sons of Míl Espáine) came to the island. It’s believed that the Celtic invaders pushed the Tuatha Dé Danann or the Aos Sí into the Otherworld – the magical realm they now inhabit which is also viewed as the Aos Sí kingdoms in the hills and mounds of Ireland.

Historic Origins

The most likely historic origin of the Aos Sí reaffirms the Tuatha Dé Danann connection – Ireland was indeed inhabited by other tribes of people when the ancient Celts invaded from Iberia around 500 BC.

The Celts succeeded in their conquest and archeologists today have found many burial grounds (often mass burial grounds) of the ancient inhabitants of Ireland.

This makes the idea of the Aos Sí living underground in Ireland’s hills and mounds much more gruesome, but that’s indeed how mythologies usually start.

The People Of Many Names

Celtic mythology is diverse and historians have been studying it through the lens of several modern cultures (mainly the people of Ireland, Scotland, Wales, Cornwall, and Brittanny). In the same way, the names of the Aos Sí are also diverse.

  • For one, they were called Aes Sídhe in Old Irish or Aes Síth in Old Scottish (pronounced [eːs ʃiːə] in both languages). We have also already explored their likely connection with the Tuatha Dé Danann.
  • In modern Irish, they are also often called Daoine Sídhe (Daoine Síth in Scottish). Most of these terms are usually translated as The People of Mounds – Aes being people and Sídhe meaning mounds.
  • The fairy folk are also often called just Sídhe. This is often translated as just fairies even though that’s not technically true – it literally just means mounds in Old Irish.
  • Another common term is Daoine Maithe which means The Good People. It’s also interpreted as The Good Neighbors, The Fairy Folk, or just The Folk. There is some discourse among historians whether the Daoine Maithe and the Aos Sí are the same things. Some believe that the Daoine Maithe are a type of Aos Sí, while others believe that they are two completely separate types of beings (Aos Sí being fallen angels and the Daoine Maithe being the Tuatha Dé Danann). However, the prevailing belief seems to be that they are different names for the same type of beings.

Converging Worlds

Whether the Aos Sí live in their underground mound kingdoms or in a whole other dimension, most ancient myths agree that their realm and ours merge around dawn and dusk. The sunset is when they cross from their world to theirs, or exit their underground kingdoms and start roaming the Earth. Dawn is when they go back and hide.

Are the Aos Sí “Good” or “Evil”?

The Aos Sí are generally viewed as being benevolent or morally neutral – they are believed to be a culturally and intellectually advanced race compared to us and most of their work, life, and goals don’t really concern us. The Irish don’t begrudge the Aos Sí for treading their land at night as they realize that the land actually belongs to the Aos Sí as well.

At the same time, however, there are quite a few examples of malevolent Aos Sí, such as the Leanan Sídhe – a fairy vampire maiden, or the Far Darrig – the evil cousin of the Leprechaun. There’s also the Dullahan, the famous headless horseman, and of course, the Bean Sídhe, colloquially known as the banshee – the Irish harbinger of death. Still, these and other evil examples are typically seen as the exception rather than the rule.

Symbols and Symbolism of the Aos Sí  

The Aos Sí are quite simply “the Old Folk” of Ireland – they are the people the Irish Celts know they replaced and whose memory they have tried to preserve in their mythology.

Like the magical folks of other mythologies, the Aos Sí are also used as an explanation for everything the people of Ireland couldn’t explain and viewed as supernatural.

Importance of the Aos Sí in Modern Culture

The Aos Sí are rarely depicted by name in modern fiction and pop culture. However, their fairy-like interpretation has been featured in countless books, movies, TV shows, plays, and even video games and music videos over the years.

The various types of Aos Sí have also seen thousands of depictions in books, movies, and other media – banshees, leprechauns the Headless Horseman, vampires, flying ghosts, zombies, the boogieman, and many other famous mythological creatures can all trace their origins partly or entirely to the old Celtic mythology and the Aos Sí.

Wrapping Up

As with the origins of most legends and myths, the stories of the Aos Sí represent the ancient tribes of Ireland. In the same way that Christianity preserved and changed many stories of Celtic mythology after they took over the Celtic regions, the Celts also, in their time, had stories about the people that they replaced.

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Yordan Zhelyazkov
Yordan Zhelyazkov

Yordan Zhelyazkov is a published fantasy author and an experienced copywriter. While he has degrees in both Creative Writing and Marketing, much of his research and work are focused on history and mythology. He’s been working in the field for years and has amassed a great deal of knowledge on Norse, Greek, Egyptian, Mesoamerican, Japanese mythology, and others.