Conn Cétchathach

Conn Cétchathach was high king of Ireland, before the birth and early childhood of Finn Mac Cumhaill. He was often called Conn Cétchathach – "Conn of the Hundred Battles".

His grandfather was Tuathal Techtmar, who was high king of Ireland. There are some uncertainties about who his parents were. Conn was either the son of Fedlimid Rechtaid or that of Óenlám Gaba; his mother was probably Medb Lethderg.

Conn was married to Eithne Tháebfhota, who was the daughter of Cathair Mór, and became the father of Art and Connla, and he was the grandfather of Cormac Mac Airt. However, Conn married a Danann woman named Bé Chuma, who was banished from the sidhe. According to Echtrae Airt meic Cuinn (The Adventure of Art Son of Conn), Bé Chuma caused the land in Ireland to become blighted. The land was restored only after Art fetched Delbcháem daughter of Morgán and banished Bé Chuma from Ireland.

Conn won the kingship by ousting Cathair Mór. Either Conn or Goll Mac Morna had killed Cathair Mór. Conn won his name Cétchathach ("of Hundred Battles") from his war against the petty kingdom of Dal nAraide. Conn then married Cathair's daughter.

Eógan Mór, also known as Mug Nuadat, was the king of Munster and Conn's main rival. Munster was virtually an independent kingdom. They fought many battles, until Eogan was killed at the Battle of Mag Léna.

During his reign, Goll, the chieftain of Clan Morna, challenged Cumhaill (chieftain of Clan Baiscne), for the leadership of the Fianna. It was said that Conn and his druid adviser Tadg used Goll in a plot against Cumhaill, who had shown too much independence. When Cumhaill was killed in battle against Clan Morna, Conn appointed Goll as captain of the Fianna (rígfhéinnid).

Conn was said to have died when thirty Ulster warriors dressed as women attacked and killed him. The leader of the assassins was Tiobraide Tireach.

Conaire Cóem, son of Mog Lama and Conn's kinsman by marriage, succeeded him and ruled as High King for eight years before Conn's own son, Art Óenfher, became high king.