Flourished in the early 400s. Migrated into Garthmadrun from Dyfed with his son Cormac. 1
Urb was the son of Aed Brosc and, like his father, was a Deisi chieftain and warrior in the late fourth century. The Deisi had fled Ireland two generations earlier after a failed bid for independence had infuriated the Irish High King. The homeless Deisi were employed as mercenaries in 382 AD by Magnus Maximus, the Commander of Britain and later Western Roman Emperor. In return for protecting the kingdom of Demetia (later to become Dyfed), the Deisi were given land along the coast. Aed Brosc is thought to have died sometime around 405 AD and it's presumed that Urb, as his eldest son, inherited his leadership.
Very little is known of Urb. Presumably he and the rest of the Deisi continued to defend the Dyfed coast against Irish raiders. Urb had at least one son, Cormac, and a younger brother, Triffyn, who would go on to marry Gweldyr, the sole heiress of Demetia and become King of Dyfed. At some point in the 390s, Urb moved his family east to the Brecon Beacons where, two generations later, his grandson, Brychen, would found the kingdom of Brycheiniog in the mid-fifth century. His death is not recorded and it's probable that his son, Cormac, became the chieftain of the Deisi. 2