How ogham is written
Each ogham letter is one to five strokes or notches cut across or beside a stem line. On a standing stone the stem was usually the stone’s edge, read from the bottom up. Most of the roughly 400 surviving inscriptions, in Ireland and western Britain, date from about the 4th to the 6th century, and many are simply a person’s name and their father’s.
The four groups
The letters come in four groups of five, called aicmí, each named after its first letter: b l f s n, then h d t c q, then m g ng z r, and the vowels a o u e i. Medieval scholars later added a few extra letters, the forfeda; the chart includes peith, which is used for p.
Medieval scholars also linked the letter names with trees, such as beith with birch, which is why ogham is often called the Celtic tree alphabet. For some letters the tree link is doubtful.
Writing English in ogham
Ogham has no letters for j, k, v, w, x or y. The ogham translator borrows the closest ones: k is written with coll, v and w with fearn, and j and y with iodhadh.
Sources & method
Every ogham character’s code point and Unicode name was checked against the Unicode Character Database 16.0, for example ᚁ is U+1681 OGHAM LETTER BEITH; the letter names on the chart are the Unicode names.
Checked against
- Unicode Ogham code chart (U+1680–U+169F)names and code points of every letter and mark on the chart