Eochu was son of Finn, son of Fionnlogh, son of Rogen Ruad, son of Essamain Emna, son of Blathnachta, son of Labraid Lorc, son of
Enna Aignech. Various Middle Irish tales give him a large family. With his wife
Cloithfinn, he had six daughters (Derbriu, Eile,
Mugain, Eithne,
Clothru and
Medb) and four sons (the triplets known as the
findemna, and Conall Anglondach). Derbriu was the lover of
Aengus of the
Tuatha Dé Danann. Her mother-in-law, Garbdalb, turned six men into pigs for the crime of eating nuts from her grove, and Derbriu protected them for a year until they were killed by Medb. Four of Eochu's daughters married
Conchobar mac Nessa after he became King of Ulster, making him Eochu's son-in-law four times. The daughters were Mugain, Eithne, Clothru and Medb. The quad-wedding was compensation for the death of Conchobar's father, Fachtna Fáthach. According to one tradition, Clothru gave birth to Conchobar's eldest son,
Cormac Cond Longas. However, other traditions make him the son of Conchobar with own mother,
Ness. With Eithne Conchobar had a son,
Furbaide. After Medb drowned Eithne, Furbaide was born by posthumous
caesarian section. Medb bore him a son called Amalgad. After Medb later left Conchobar, Eochu made her Queen of Connacht. Some time after that, Eochu held an assembly at Tara, which both Conchobar and Medb attended. The morning after the assembly, Conchobar followed Medb down to the
river Boyne where she had gone to bathe, and raped her. Eochu made war against Conchobar on the Boyne, but was defeated. The three
findemna tried to overthrow their father in the Battle of Druimm Criaich. The night before the battle, their sister
Clothru, afraid that they would die without an heir, seduced all three of them, and the future High King
Lugaid Riab nDerg, was conceived. The next day they were killed, and their father, seeing their severed heads, swore that no son should directly succeed his father to the High Kingship of Ireland. == Rule and death ==