He is also mentioned by Bede under the name of Reuda,[103] as the leader of the Scots who came from Hibernia to Alba.
Three centuries later, a fresh colony of Dalriadans laid the foundation of the Scottish monarchy under Fergus, the son of Erc.

Mac Con was the next Ard-Righ or chief monarch of Ireland.

He obtained the royal power after a battle at Magh Mucruimhe, near Athenry, where Art the Melancholy, son of Con of the Hundred Battles, and the seven sons of Oilioll Oluim, were slain.
The reign of Cormac Mac Airt is unquestionably the most celebrated of all our pagan monarchs.

During his early years he had been compelled to conceal himself among his mother's friends in Connaught; but the severe rule of the usurper Mac Con excited a desire for his removal, and the friends of the young prince were not slow to avail themselves of the popular feeling.

He, therefore, appeared unexpectedly at Tara, and happened to arrive when the monarch was giving judgment in an important case, which is thus related: Some sheep, the property of a widow, residing at Tara, had strayed into the queen's private lawn, and eaten the grass.