Venedotia or sometimes Vendotia, is the Latin name for north-west Wales, in the Brythonic Venedos, which later became mutated into the Welsh as Gwynedd, and adopted as the name of the kingdom that existed between the sixth and thirteenth centuries.
Our evidence for the use of the name Venedotia comes from an inscribed stone (technically known as PMCH1/3) found at the church in Penmachno in north Wales (and within the territory of Gwynedd) that features the Latin inscription;
CANTIORI HIC IACIT VENEDOTIS CIVE FVIT CONSOBRINO MA--LI MAGISTRATI
Here lies Cantiorios, citizen of Venedotia. He was cousin of Mael(?) the magistrate.
The stone has been dated to sometime in the period 400 to 525 AD and is unique to the period and location in its use of the Roman terms of civis (citizen) and magistratus (magistrate). The use of such terms in the late fifth century points to the existence of an ordered system of government along Roman lines in north-west Wales during the Sub-Roman period.
For further details of PMCH1/3 see