Ogham is sometimes referred to as the Celtic Tree Language as each letter was named after a tree the people were familiar with, and used.Ogham inscriptions consist almost exclusively of personal names and marks, possibly indicating land ownership, though some appear to be memorials to the dead.
Any wood Ogham inscription have, of course, long vanished. However, there are roughly 400 Ogham inscriptions in stone found to date, of which 330 are from Ireland. The other Ogham stones have been found in England, Scotland, Wales, Isle of Man and Shetland.
The Irish had no other written alphabet until Christian missionaries introduced Latin. Ogham ceased to be used after the first few centuries of the Christian era, as the use of inscription language was reviled as a pagan practice.