The inscription, dating to the early medieval period, commemorates "Rialobranus son of Cunovalus."

[2] The inscription, in debased Roman capitals, reads "Rialobrani Cunovali fili", which translates as "Rialobranus son of Cunovalus."

Rialobran (or Ryalvran) may be Cornish for "royal raven", whereas Cunovallos may be British for "famous leader" (being cognate to the second element in the surname McConnell), thus the inscription would read "royal raven son of famous leader".

[2] The antiquarian William Borlase described the stone in 1769: at that time it was lying prostrate on the ground.

[6] A popular tradition stated that a battle was fought nearby, and that Riolbranus was slain and buried at the spot.