After the fall of Urien, Llywarch was given the task of returning to Rheged with Urien's severed head. The kingdom fell to Urien's son Owain, who was slain at the Battle of Catraeth, along with almost the entire host of Britons, including all of Llywarch's sons. His friends and family all dead, he is advised to flee to the court of Cynddylan in the Kingdom of Powys. When Cynddylan was slain in battle, Llywarch was left friendless and destitute, with nothing but the milk from a single cow to support him. According to legend, he lived in a hut at Aber-Ciog (now called Dol-Giog), alone with his harp, composing his poems (which would have been sung). At this point, a monk associated with Llanfor in Meirionydd, near Llyn Tegid in Gwynedd, is said to have taken pity on him, converted him, and witnessed his happy death. Near this site, there is a mound known as Pabell Llywarch (Llywarch's Tent), and further south lies "Clawdd Llywarch Hen" (Llywarch Hen's Dyke).