Supposedly the founder of the town of Pickering (North Yorks), Peredyr Steel-Arms and his twin-brother, Gwrgi - the sons of King Eliffer Gosgorddfawr - ruled Ebrauc jointly. According to Welsh legend, their father was killed when they were still young and the Queen brought her two boys up alone. Peredyr spent much of his life wreaking vengance on his father's killers.

The Joint-Kings of Ebrauc are best known for their victory over King Gwenddoleu of Caer-Wenddoleu (Carwinley) at the Battle of Arfderydd, now Arthuret in Cumbria. In AD 573, the Yorkist Kings allied themselves with King Riderch Hael of Strathclyde and possibly King Dunaut Bwr (the Stout) of the Northern Pennines. They marched north to claim the disputed land around Caer-Laverock from Gwenddoleu. The King of Caer-Wenddoleu was killed in the battle and his bard, Myrddin or Merlin, one of the few survivors, was forced to flee into the Caledonian Forest. Peredyr was unable to take advantage of his victory however and, seven years later, when his army again marched north, this time to put down the troublesome Anglians of Bernicia, he and his brother were both killed by King Adda's forces at Caer-Greu (location unknown). The Deirans then rose up, under King Aelle, and moved on the City of Ebrauc, forcing Peredyr's son to flee the Kingdom.