King of Ulster
Conchobar mac Nessa was the king of Ulster, lord of Emain Macha, and the ruler whose court was the setting for the entire Ulster Cycle. He was not the greatest warrior of the court — that was Cú Chulainn. He was the king whose decisions caused the catastrophes, and who lived to see the consequences without being able to undo them.
His mother Nessa was the dominant force in his origin story. She negotiated with the previous king of Ulster, Fergus mac Róich — let her son have the kingship for one year, and she would sleep with him. Fergus agreed. The year ended, the people preferred Conchobar, and the kingship didn’t come back. Fergus remained at court as the greatest champion of the king who had replaced him.
Conchobar’s greatest failure was Deirdre. The druid Cathbad had prophesied at her birth — before she was even born, from inside her mother’s womb — that she would be the most beautiful woman in Ireland and that great ruin would come to Ulster through her. The Ulstermen wanted her killed on the spot. Conchobar overruled them: he would have her raised in seclusion, to become his own wife when she came of age. That decision made the prophecy certain.
Deirdre chose Naoíse instead. They fled to Scotland. When Conchobar sent Fergus mac Róich to Scotland as a personal guarantor of their safe return — Fergus’s word being the one guarantee in Ulster that could not be broken — Conchobar broke it. The sons of Uisneach were killed on their return. Fergus left Ulster in rage and took his sword to Medb‘s court at Connacht. The loss of Fergus before the Táin Bó Cúailnge was the direct cost of Conchobar’s betrayal.
He had a calcified brain-ball — a sling-projectile made from a human brain — lodged in his skull from a battle wound that couldn’t be removed without killing him. He lived with it for years, forbidden from excitement or exertion. He died when he heard about Christ’s crucifixion. He raged so violently at the injustice of it that the brain-ball burst from his skull.
His genealogy gave his kingship deep roots — he was descended from Rudraige mac Dela of the Fir Bolg through the Ulster dynastic line. He was the uncle of Cú Chulainn through his sister Deichtine. The king and the champion of his court were bound by blood as well as loyalty.
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