How a god fathered the greatest hero Ulster ever had
Every great hero needs an extraordinary beginning, and Cú Chulainn — the greatest warrior in Irish mythology — started his life with not one but two fathers, a divine conception, and a first birth so complicated that he had to be born twice. Even before he picked up a sword, his origin story was unlike anyone else’s.
His mother was Deichtine, the sister of the Ulster king Conchobar mac Nessa. His father — in the version that the tradition settled on — was the god Lugh of the Long Arm, the master of every skill, the god who had killed Balor of the Evil Eye at the Second Battle of Mag Tuired. Which makes Cú Chulainn the son of a god and the nephew of a king — a hero with divine blood running through him from the very beginning.
The Mysterious Flock of Birds
The story begins with a flock of magical birds descending on the plain of Emain Macha — the great royal site of Ulster — and eating every blade of grass within sight. King Conchobar and his warriors gave chase in their chariots, following the birds through the night as they flew south. At nightfall, the warriors lost sight of them and took shelter in a small house they found on the plain. Inside they found a young couple — a beautiful woman and a man who welcomed them and fed them royally.
That night, Deichtine — who was with the hunting party — helped the young woman of the house give birth to a baby boy. In the morning the couple and the house had vanished. Only the baby remained. Deichtine took him home and raised him as her foster-son. But the baby died young, and Deichtine was devastated.
The God Speaks
Then Lugh appeared to her in a dream and told her the truth. He was the man she had sheltered. The woman was his wife. He told Deichtine that she was pregnant — with his child — and that the boy should be named Sétanta. The child of the divine host she had welcomed was gone, but the child of the god himself was already growing.
A Complicated Beginning
The politics of the situation were awkward. Deichtine was already betrothed to a Ulster warrior named Sualtam mac Róich. A pregnant bride was complicated. She drank a cup of liquid — some versions say it was given to her, some that she chose it — and the pregnancy was temporarily resolved. Then she married Sualtam, and nine months later the boy was born again, properly this time, in every sense: the same divine child, the same soul, the same destiny. He was given to foster-parents to be raised, as was the noble custom, and eventually he grew into the warrior the world would know as Cú Chulainn.
Key facts about Cú Chulainn
- Irish title: Compert Con Culainn (“The Conception of Cú Chulainn”)
- Hero’s birth name: Sétanta — later renamed Cú Chulainn
- His mother: Deichtine — sister of King Conchobar mac Nessa of Ulster
- His divine father: Lugh of the Long Arm — master of every skill; the god who slew Balor
- His human foster-father: Sualtam mac Róich — Ulster warrior who married Deichtine
- Born twice: The divine conception preceded his physical birth; born first in a mysterious house, then properly to Deichtine
- Raised by: Multiple foster-parents, as was the custom for noble children
- Cycle: Ulster Cycle
Link/cite this page
If you use any of the content on this page in your own work, please use the code below to cite this page as the source of the content.
Link will appear as The Birth of Cú Chulainn: https://irishgodsandgoddesses.net - Irish Gods & Goddesses, March 22, 2026