 The diocese was founded for the minor sub-kingdom of the Magonsæte in 676.It now covers the whole of the county of Herefordshire, southern Shropshire and a few parishes in Worcestershire, Powys and Monmouthshire.The arms of the see are "gules, three leopard's faces reversed jessant-de-lys or", which were the personal arms of Bishop Thomas de Cantilupe (d.1282).