[1] The earliest reference to Cairbre is in Tírechán's Memoir of St. Patrick, a 7th-century Latin text found in the Book of Armagh.
The giant says he was killed by the sons of Mac Con during the reign of Cairbre Nia Fer, a hundred years previously – i.e. in the 4th century.
[3] The 11th century Lebor Gabála Érenn places him during the reign of the High King Eterscél, which it synchronises his reign with that of the Roman emperor Augustus (27 BC - AD 14) and the birth of Christ, and makes him a contemporary of the provincial kings Conchobar mac Nessa of the Ulaid, Cú Roí of Munster and Ailill mac Máta of Connacht.
After the Ulaid win the battle, Cairbre's son Erc swears allegiance to Conchobar, marries Cúchulainn's daughter Finnscoth, and becomes king of Tara in his father's place.
After avenging Cúchulainn, Conall Cernach brings Erc's head back to Tara, where Achall dies of grief for her brother.