Ogham - The Celtic Tree Alphabet

The research for last week's language overview (Irish) brought me to the old Ogham alphabet, or Celtic Tree Alphabet, an alphabet consisting of horizontal, vertical and diagonal lines.

The name "Celtic Tree Alphabet" originates in the tradition of associating tree names to the various letters. The Ogham alphabet was used to "write" on materials like wood and stone which explains why it only used lines, no round shapes: The letters were carved into the harder surface. They are grouped in four groups of five letters each, summing up to a total of twenty different letters. Ogham was written vertically from the bottom to the top.

There are still about 400 to 500 (sources vary) stone inscriptions in Ogham writingwhich are spread throughout Ireland and Great Britain, though most of them can be found in south-eastern Ireland. They mostly are names like "X son of Y". The Ogham alphabet was used for Primitive Irish and Old Irish until it was replaced by the Roman alphabet after the 6th century.

There is no agreement as to the Ogham alphabet's origins. Some claim it was based on old runes, others say it originates from the Latin alphabet, and a third group thinks that the Ogham alphabet developed independently.

Read more:

Omniglot: a very good overview over the various letters, with name and assigned tree

The Ogham Stone: in-depth information