 It was the tribal capital of the Demetae, the Celtic tribe that inhabited the area.Various archaeological artefacts have been uncovered locally, and can be seen in the County Museum.Rhyd-y-gors Castle was constructed on the order of King William II 1087–1100, known as "Rufus", by the Norman invader William Fitz Baldwin, Sheriff of Devon, in the late 11th century (1093–1094).