Ogan, a writing system of the early Irish language, probably developed in southern Ireland during the AD 300s. Consisting of short horizontal and diagonal lines that met or crossed a base line, it is found in Ireland and parts of Wales, Scotland, south-west Britain and the Isle of Man, where Irish influence or settles were found. Typically ogan inscriptions were short commemorative textes carved into the edges of free-standing stones, as a dedication to named individuals usually of high or ecclesiastical status.

This red sandstone memorial comes from Devon, south-west Britain, which at this time belonged to the British kingdom of Dumnonia. Once part of Roman Britain, Irish groups settled the region during the late AD 400s. The resulting cultural interplay is reflected in the Latin and Ogam inscriptions on this stone.

On this face, a Latin inscription commemorate Fanonus, son of Rinus, while the ogam inscription around the edges may describe the same dedication. On the other face, a Latin inscription commemorating Sagranuus is perhaps a later addition. Irish linguistic features hint that the inscriptions were made under Irish influence or even for an Irish speaker. But the shape of the Latin lettering and the custom of erecting stone memorials to the dead follow Roman traditions, preserved in the region long after Rman control had ended.