Cynllibiwg

Cynllibiwg (or some variation) was evidently a place name in early medieval Wales.

The earliest surviving reference to it is in the Historia Brittonum, which describes a marvelous spring in the regione of Cinlipiuc that has an abundance of fish despite not being fed by a stream.^[1] John Edward Lloyd notes that this Cinlipiuc appears to be one of the various district names created by adding the element -wg to a personal name, in this case an unknown Cunalipi or Cynllib.^[2] The Domesday Book refers to a place called Calcebuef, which rendered ten shillings; one editor suggests this is a corruption of Cynllibiwg and that it derives ultimately from the name of Saint Cynllo.^[3] However, Lloyd connects this name instead to the cantref of Buellt.^[4] The Red Book of the Exchequer, a mainly 13th-century compilation, mentions a region of seven cantrefs between the Severn and the Wye that had been known as Kenthlebiac during the time of Rhys ab Owain of Deheubarth (died 1078).^[5] This would place Cynllibiwg in the region later known as Rhwng Gwy a Hafren, but reveals nothing about its extent and nature. The editor suggests that seven cantrefs should be amended to three, perhaps Arwystli, Maelienydd, and Elfael; these are mentioned earlier in the list as part of Powys in the time of 'Meic Menbis', but no longer such.^[5]

It has been postulated as an early kingdom,^[6] but is not mentioned by the great majority of historians.^[7]