The Mabinogion

And these five divided it amongst them, and because of this partition are the five divisions of Ireland still so termed. And they examined the land where the battles had taken place, and they found gold and silver until they became wealthy.

And thus ends this portion of the Mabinogi, concerning the blow given to Branwen, which was the third unhappy blow of this island; and concerning the entertainment of Bran, when the hosts of sevenscore countries and ten went over to Ireland to revenge the blow given to Branwen; and concerning the seven years’ banquet in Harlech, and the singing of the birds of Rhiannon, and the sojourning of the head for the space of fourscore years.