retained its borough status until the 19th century. Etymology Cefnllys derives from the Welsh words , meaning 'ridge', and , meaning 'mansion' or 'court'. is associated with the unfortified courts of medieval Welsh rulers and may refer to the administrative manor () of a local lord. The name is first mentioned in 1246 as Keventhles and the form Kevenlleece, standard in the 19th century, is recorded by 1679. Another name for the settlement and parish, ("church of St Michael at Cefnllys"), appears in records and refers to the medieval church which still stands. An older name, (also and ), meaning "fort on the River Ieithon" ( being Old Welsh for 'fort', cognate with dun), is also related to fortifications at Cefnllysparticularly the earlier Norman castle, which is sometimes called "Cefnllys Old Castle". Dinieithon or ("shire of Dinieithon") was the name of the commote within the cantref (hundred) of Maelienydd. Location The isolated ridge of Castle Bank is located east of the modern town of Llandrindod Wells, Powys. It occupies a key position at the junction of several tributary valleys of the River Ithon, granting commanding views over an important communication corridor into central Wales. Cefnllys was (administrative centre) of Maelienydd, part of the Welsh region of Rhwng Gwy a Hafren (). As the English Marcher lords expanded their control westward, Maelienydd formed a core part of the turbulent area known as the middle march, together with Gwrtheyrnion and Elfael. The castle was viewed as a forward defence against Welsh incursions by towns along the English border, particularly Hereford. Description Castle Bank is a naturally defensible position, protected on three sides by a loop of the River Ithon. The hill is open access land, and the highest point is above sea level. The mottes of two castles are situated at opposite ends of the hill, the ruins heavily deformed and mostly rubble; only their basic characteristics have been identified. The earlier northern castle consisted of a keep within an elevated triangular inner bailey, with an accompanying outer bailey which may been entered via a gatehouse at its north-east corner. The main feature of the later southern castle was a circular (or octagonal) tower inside a walled court, separated from the main part of the ridge by a deep rock-cut ditch. There was probably a small bailey to the south-west, and a scarp across the main ridge suggests the southern half of