Bryn Kyvergyr is the hill on the bank of the Cynvael River where Gronw Pebyr lies in wait for Llew Llaw Gyffes. Known in the account also as Bryn Cyvergyr, it is a carefully prepared ambush site whose role in Llew’s wounding leads directly into Gronw’s seizure of power in the surrounding territories.

Setting and Preparation

The hill stands beside the Cynvael River, opposite the bank to which Blodeuwedd has arranged for the Cantrev’s goats to be driven. That placement helps draw Llew to the river crossing: Blodeuwedd presents the animals as the bucks he had described, and Llew agrees to demonstrate how he could stand with one foot on a cauldron’s edge and the other on a buck. While the bath is prepared, Gronw waits concealed on the hill.

The Ambush

When Llew steps from the bath and takes the unusual position, Gronw rises from Bryn Kyvergyr and throws a poisoned dart, wounding him. Llew then flies away in the form of an eagle. The scene makes the hill more than a landmark: its position across the river gives Gronw a concealed vantage over the staged demonstration and makes it the place from which the attack is launched.

Aftermath and Significance

After Llew disappears, Gronw and Blodeuwedd go together to the palace. The following day, Gronw takes possession of Ardudwy; after overcoming the land, he rules over both Ardudwy and Penllyn. The narrative thus links a precisely located ambush to a territorial reversal: the attack from Bryn Kyvergyr is followed by Gronw’s assumption of rule.