Pengwern

Early Powys, much larger in extent than the later medieval kingdom, seems to have roughly coincided with the territory of the Celtic Cornovii tribe, whose civitas under Roman rule (capital or administrative centre) was Viroconium Cornoviorum (now Wroxeter)[citation needed], replacing a fort located on the Wrekin, which was abandoned.

[2] Between 530 and 550, Viroconium Cornoviorum, like many other Roman urban sites and villas in Britain at the time, was abandoned, possibly eventually developing into part of the royal court of Llys Pengwern.

[9][10] Cynddylan apparently joined forces with king Penda of Mercia to protect his realm, possibly also for personal reasons: his brother Gwion had been killed during the Battle of Chester.

Regardless, this seems to have bought a period of peace until Penda's death, when a Northumbrian raiding party led by Oswald's brother Oswiu of Northumbria overran northern Mercia and, a bit later, Cynddylan's palace at Llys Pengwern in a surprise attack.

Caught completely off guard and without defence, the royal family, including the king, were slaughtered, according to the poetry commemorating the tragedy, with the palace being burned to the ground, likely along with records.