Eriu, Banha and Fodla

Eriu and her two sisters, Banha and Fodla, had given their name to Ireland before the arrival of the Milesians. They were the incarnation of Ireland, represented as the Sovereignty of Ireland, who wedded kings to ensure the prosperity of the isle.

Eriu and her sisters had been named as daughters of Fiachna and Ernmas in the Lebor Gabála. Fiachna was actually Ernmas' son by a Danann named Delbáeth who was the son of either Ogma or Angus. In the same work, she was also called the daughter of Dealbaeth (Delbáeth). This means that Eriu and her sisters were also the sisters of Morrigan, Badb and Macha.

As Eri, Eriu fell in love with a Fomorian king named Elatha, the son of the Fomorian Delbáeth (son of Neit). Most Fomorians were ugly and deformed. Elatha was a beautiful son of Delbáeth and the grandson of Neit (this Delbáeth should not be confused with another Delbáeth, who was a Danann and son of Ogma or of Angus). Elatha was described as having golden, curly hair. Elatha seduced her, and she became the mother of Bres. Elatha gave her a ring so that he would later recognise his own son.

Bres became a king of Ireland when Nuada lost his right hand, but because of her son's oppressive rule, the Danann had Bres expelled. Bres took the matter to his mother, and Eriu took her son to see her former lover. Elatha recognised his son because Bres wore the ring that the Fomorian king had given to Eriu. Elatha and the other Fomorian kings raised an army against the Danann.

After the Danann defeated the Fomorians in the second battle of Mag Tuired, it seemed that Lugh Lamfada married Eriu. Lugh seemed to have many wives. An unnamed wife had an affair with Cermait, the son of Dagda. Out of jealousy and revenge, Lugh killed Cermait. The sons of Cermait killed Lugh in turn. Note that this contradicted that Lugh was alive to be the father of Cú Chulainn. (See Lugh)

Then Eriu married MacGreine, the son of Cermait. Her other sisters also married the sons of Cermait: Banba was married to MacCuill, while Fodla was the wife of MacCecht. Their husbands ruled Ireland after the war, until the Milesians invaded. The Milesians named Ireland "Erin," after Eriu.

In the Battle of Tailtiu, Eriu and all of her sisters, along with their husbands, were killed by the Milesians. A Milesian named Suirge killed Eriu. (See Coming of the Milesians.)