Ogham script is an early form of Old Irish and the first known Irish writing. The characters comprise a series of lines and notches that are scored across a long stem-line often on standing stones. In the majority of cases the inscription is read from the bottom up, and usually names the person being commemorated along with their ancestors and the carver of the inscription

Over 350 Ogham stones are known, with the majority found in southern Ireland from Kerry to Waterford and in South Leinster. They also occur in small numbers in western Scotland, the Isle of Man, and in Cornwall at Lewannick, where Irish settlers from Munster landed and founded communities. While the stones in Ireland are written purely in Ogham, those in Britain often have the Ogham inscription repeated in Latin carved in Roman characters on the same stone.

In legend Ogham was said to have been created by Ogma, the son of An Dagda. Ogma was both a warrior and the god of eloquence and literature, and fought the second battle of Magh Tuireadh where he slew the Formi, Indech, son of the goddess Domnu.