Ogham inscription
（重定向自CIIC）
![Ogham stone CIIC 504 from the Isle of Man showing the droim in centre. Text reads BIVAIDONAS MAQI MUCOI CUNAVA[LI],
or in English of Bivaidonas, son of the tribe Cunava[li]](/uploads/202501/04/CIIC_5044802.gif)
There are roughly 400 known ogham inscriptions on stone monuments scattered around the Irish Sea, the bulk of them dating to the 5th and 6th centuries. Their language is predominantly Primitive Irish, but a few examples record fragments of the Pictish language. Ogham itself is an Early Medieval form of alphabet or cypher, sometimes known as the "Celtic Tree Alphabet".