The Battle of Chester (Old Welsh: Guaith Caer Legion; Welsh: Brwydr Caer) was a major victory for the Anglo-Saxons over the native Britons near the city of Chester, England in the early 7th century. Æthelfrith of Northumbria annihilated a combined force from the Welsh kingdoms of Powys and Rhôs (a cantref of the Kingdom of Gwynedd), and possibly from Mercia as well. It resulted in the deaths of Welsh leaders Selyf Sarffgadau of Powys and Cadwal Crysban of Rhôs. Circumstantial evidence suggests that King Iago of Gwynedd may have also been killed. Other sources state the battle may have been in 613 or even as early as 607 or 605 AD. According to Bede, a large number of monks from the monastery at Bangor on Dee who had come to witness the fight were killed on the orders of Æthelfrith before the battle. He told his warriors to massacre the clerics because although they bore no arms, they were praying for a Northumbria defeat. The strategic significance of the battle remains unclear as Æthelfrith died in battle soon after the victory. However other historical accounts hold that Æthelfrith died in 616 AD by Rædwald of East Anglia, at the Battle of the River Idle. It has been suggested that Cearl, the Anglo-Saxon king of Mercia, may have also been involved and shared in the Britons' defeat because his overkingship of eastern Wales and Mercia effectively ended until the rise of his successor, Penda by 633. Historical sources Battle Historian Charles Plummer, best known as an editor of Bede, believed that the battle occurred around 615 or 616, but near contemporary annals give a variety of dates. The Anglo-Saxon Chronicle says, for year 605 in one version and year 606 in another version: And here Æðelfrið led his army to Chester, and there slew countless Welsh. And came about Augustinus's prophecy, that he said "If they do not have peace with us, they will die at the hands of the Saxons." There also were slain 200 priests who came there to pray for the Welsh army. Scrocmail was called their leader, and he escaped as one of fifty." In the Brut y Brenhinedd (), which is a collection of variant Middle Welsh versions of Geoffrey of Monmouth's Latin chronicle Historia Regum Britanniae (History of the Kings of Britain), the battle is called Perllan Fangor (). Brut proved especially influential in medieval