Flat Holm and Steep Holm islands in the Bristol Channel have names derived from a Scandinavian word for an island in an estuary, suggesting it’s from here the Vikings launched raids in the area during the Dark ages.
Following the Norman Conquest, the area was divided into manors with the Barry area split into two large lordships, Penmark and Dinas Powys.
Penmark was split into the sub-manors of Fonmon, West Penmark and Barry. Dinas Powys was split into the sub-manors of Cadoxton and Uchelolau. The sub-manor of Barry was granted to Odo, a Norman Knight, who assisted in the Norman Conquest of England during the 11th century. As reward for his military services, Odo was granted estates in Pembrokeshire and around Barry, Wales, including Barry Island.
Odo’s grandson, Gerald of Wales, gives the origin of his family’s name, de Barry, in his Itinerarium Cambriae (1191): “Not far from Caerdyf is a small island situated near the shore of the Severn, called Barri, from St. Baroc …. From hence a noble family, of the maritime parts of South Wales, who owned this island and the adjoining estates, received the name of de Barri.”
They established their seat at Barry Castle, on high ground overlooking the Bristol Channel, a site occupied in Roman times by a native homestead.