The two names are latinised Celtic: rigalo-branos (regal/royal raven) and cuno-ualos (worthy/powerful hound). In modern Cornish they would be: Rialvran and Kenwal. The insciption has been dated to the middle third of the 6th century AD. Inscribed stones like this are Christian memorials (and indeed, the I of Rialobran is extended to form part of an incised cross) which were set up in early church enclusres or - like this one - beside ancient and important trackways. Its antiquity is not in doubt, just the extent of it. It could well have been an existing Bronze Age menhir reused as an early Celtic Christian memorial stone. Other Bronze Age sites, including the Men-an-Tol stone circle, are close by.