The Book of Invasions: How Ireland Was Inhabited


By Jennifer Paxton, Ph.D., Catholic University of America

The pre-historic Ireland is a mystery. The Book of Invasions is believed to be a key to early Ireland, but can a book full of giants, miracles, magic, and gods really tell the history of a nation and its origins?

An illustration of a Celtic war
History tells us that Ireland was the only Celtic-speaking country not invaded by the Romans. (Image: Marzolino/Shutterstock)

How did Ireland end up as a Celtic-speaking country? History tells us that Ireland was the only Celtic-speaking country not invaded by the Romans. Still, the reason why it was a Celtic-speaking country goes far back before the Irish written history can reach. However, there is one very important text about early Ireland called The Book of Invasions. There is much scholarly debate over how much reality the book offers, but why is there so little about early Ireland?

This is a transcript from the video series The Celtic World. Watch it now, on Wondrium.

The Book of Invasions is, in fact, what the Irish thought they knew about the Irish past. The original name of this book is Lebor Gabála Érenn, which literally translates as ‘The Book of the Takings of Ireland’, but it is normally called The Book of Invasions. The book began in the eighth century but fully developed in the 11th and 12th centuries. Still, the text is incredibly difficult and confusing to read. There are numerous place-names and genealogies, every story is told first in prose and then in poetry, and the two versions usually conflict.

Learn more about Medieval Irish literature.

How The Book of Invasions Came to Be

As mentioned, Ireland was the only Celtic-speaking country that was not conquered by the Romans. This brought along two results. First, the Irish Celtic experience was independent of any Latin influence.

The second result was that Ireland remained illiterate until the conversion to Christianity in the fourth century. However, the Irish did not produce much-written text until several centuries later. By the time they started, pre-Christian Ireland and its reality were long gone, but they wrote a lot about it. Ireland has the largest body of vernacular texts in a Celtic language, as well as the largest body of texts to survive in any vernacular language from early medieval Europe.

Much of this written material was about law. Another big category is genealogical texts, as claims to the property were determined by family relationships. The next category contains texts that can be regarded as literary and includes The Book of Invasions as well. Yes, there is a huge source referring to pre-Christian Ireland, but they were all written long after the time they talk about. It is not easy to determine how much of their content is real.

Ireland’s Six Waves of Invasion

As the Book of Invasions puts it, Ireland underwent six waves of invasions until it was populated. No one lived in Ireland, but 40 days before the great flood, Cesair, granddaughter of Noah, daughter of Bith, fled to it with 50 young women and three men to stay safe from the flood. None survived the flood, though, and Ireland remained uninhabited for the next 300 years. In some other versions of the story, one poet called Fintan survived the flood, and he is the reason we know this story today.

An illustration of Noah's Ark during a rain and lightning storm.
According to the Book of Invasions, Ireland was also inhabited with the descendants of Noah. (Image: Jeevan Olesu/Shutterstock)

Descendants of Noah

The next groups who inhabited Ireland were all descendants of Noah as well, but from another son called Japhet. First, a group following Partholón, a seventh-generation descendant of Japhet, arrived. Soon after, Fomorians, the one-armed, one-legged giants, arrived and started a battle. Later, the victors were all but one killed by a plague. That one survivor told this tale into the time of Saint Columba in the 6th century.

After the plague, it took 30 years for the next group to arrive in Ireland. Followers of Nemad, a tenth-generation descendant of Japhet, sailed to Ireland by ship from the Caspian Sea. They did not enjoy a happy life there, as the Fomorians conquered the island after Nemad died of the plague. They forced Nemadians to hand over two-thirds of their wheat and milk, and even their children. Finally, the Nemadians rebelled, and only one Fomorian ship and one Nemedian ship with 30 warriors survived. The 30 warriors divided into three groups and went apart to: the northern islands, Britain, and Greece.

Learn more about Caesar and the Gauls.

Return from Greece: Ireland’s Fourth Invasion

The ones in Greece came back for the fourth invasion 230 years later. They were soil-bag carriers in Greece; thus, they were called Fir Bolg, meaning ‘Bag Men’ in Irish. The Fir Bolg fled through the Mediterranean to Ireland. They arrived to battle the northerners over their homelands. The northerners were called the Túatha de Danann, the peoples of the goddess Danu. They knew magic and took over the island in the fifth invasion with a supernatural cloud of darkness.

The Túatha practiced various crafts, and some even had some aspects of gods, such as Ogma, the patron of learning and writing. Another god-like person was Nuadu Airgetlam (Nuadu of the Silver Hand), who got his silver arm from the healer Dian Cecht after he lost an arm in the battle with the Fir Bolg. Yet, the magic and gods were not enough to bring a happy life for the Túatha, and the sixth invasion happened.

Learn more about Celtic languages in the ancient world.

How Ireland was Inhabited?

After the last invasion, Gaels permanently inhabited the island. How? Descendants of Japhet in the fourth generation started looking for a new home, leaving Egypt. Their forefather, Nél, was born at the Tower of Babel and later married Scotta (why the Irish are called ‘Scots’), the daughter of Pharaoh. Their son, Gáedel Glas was a talented linguist who combined all the 72 languages from the Tower of Babel and created Gaelic (or Irish). Later, Pharaoh died in the Red Sea when he was after Moses, and the Gaels were exiled. This is a very important voyage, illustrated in a 15th -century Scottish illustrated manuscript. The Gaels had a difficult sail over the Mediterranean. They spent the next 300 years living on the rough sea, and finally landed in Spain and conquered it. Mil, their leader, started to rule Spain, and his sons Emer and Eremon took over after his death. They also had an uncle named Ith and another brother called Amergin, who was a poet.

Gaels had built a very tall tower, from which Ith, one day saw an island far away: Ireland. He sailed there and arrived in the middle of a quarrel over the property. They asked him to judge, and he asked them why they fight in such a beautiful rich country, where there was plenty for everyone. This judgment got him killed as it was interpreted as an invasion intention.

Painting of a ship during a storm
Emer and Eremon sailed to Ireland for revenge. (Image: Yarikart/Shutterstock)

Emer and Eremon sailed to Ireland for revenge, demanding one of three things: battle, kingship, or judgment. The Túatha agreed to kingship if the brothers could sail over nine waves and return. The brothers overcame the supernatural wind by Amergin’s song. The Túatha were defeated in a battle, and the Gaels finally peopled Ireland, bringing in their culture and language. This, as the Book of Invasions, puts it, is the origin of the Irish.

Common questions about the Book of Invasions

Q: Where did the Fir Bolg come from?

In the Book of Invasions, the Fir Bolg were descendants of Nemedians who went to Greece, after the big battle with the giants. They carried bags of soil in Greece and thus were called Fir Bolg, literally meaning “Bag Men” in Irish.

Q: When was the Book of Invasions written?

The Book of Invasions of Lebor Gabála Érenn began in the 8th century, but the versions at hand today were finished in the 11th and 12th centuries.

Q: What does De Danann mean?

Túatha de Danann were the people who lived in Northern Ireland and knew magic. In the Book of Invasions, Túatha de Danann means ‘the peoples of the goddess Danu’.

Q: What does Fomorian mean?

A few of the big battles of the Book of Invasions were shaped by the Fomorians. Fomorians were the one-armed, one-legged giants that sailed around in their ships.

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