Elfael was one of a number of Welsh cantrefi occupying the region between the River Wye and river Severn, known as Rhwng Gwy a Hafren, in the early Middle Ages. It was divided into two commotes, Is Mynydd and Uwch Mynydd, separated by the chain of hills above Aberedw. In the late medieval period, it was a marcher lordship. However, after the Laws in Wales Act of 1535, it was one of the territorial units which went to make up the county of Radnorshire in 1536 (the others were Gwrtheyrnion, Maelienydd and Llythyfnwg, the latter being known in English as the lordship of Radnor).