Ogham
The Celtic tree alphabet

Ogham is the earliest alphabetic system of the Irish Celts, and frequently mentioned in their myths and sagas.

Also written as ogam or ogum, ogham is pronounced /ˈɒgəmˌ/ or /"Qg@m%/ (as if it were spelled ogg’em) or, more properly, /oːm/ or /o:m/ (like ohm, the SI unit of electrical resistance).

Its invention is ascribed to Ogma (or Oghma), god of rhetoric and eloquence; he is also called Cermait, “the honey-tongued”. His name and the word appear to be philologically (and anagramatically!) related.

The twenty original ogham letters are represented by lines or scores (for consonants) and notches (for vowels). Six later additional letters have more distinctive glyphs.

Irish myths and sagas such as the Táin bó Cúailnge (The Cattle-Raid of Cooley) mention vast libraries of Ogham writing, usually inscribed on the bark or wands of hazel, aspen, yew, or oak.

However, the only surviving primary examples of ogham are inscriptions cut on standing stones or gallán – tombstones, boundary markers, and so on. The majority of these were made between the fourth and eighth centuries CE, and they are found primarily in west Ireland – where construction and use of megalithic tombs and stone circles survived longest – but also elsewhere in the British Isles.

A 1945 survey found 121 in Kerry and 81 in Co. Cork, while others are scattered throughout the west of Ireland, Great Britain, and the Isle of Man, with five in Cornwall, about thirty in Scotland (mainly in Pictish areas), and more than forty in Wales.

Ogham is sometimes described as “crude” or “cumbrous”, but the simplicity of the letter-forms means they can easily be cut into wood or carved into stone.

The central line is, originally, the edge of the object on which the inscription is carved. This line is called the stemline or druim, which means ridge or spine (cf. modern Irish droim). (Some writers use the word flesc for the stemline, but this more properly means the wand itself; cf. modern Irish fleasc, rod.)

Ogham is read from bottom to top on standing stones, but left to right on surviving manuscript pages. There’s no evidence either way for ogham on bark and wands or in any early manuscripts (Simon Bisley has ogham running vertically on the scrolls that Sláine is reading; right).

Any piece of ogham usually begins with a feather mark: there appears to be no traditional name for this character until Macalister coined the term in 1945. Later manuscript examples – e.g., the 14th-century Book of Ballymote – end with a reversed feather mark. (A reversed feather mark would be ambiguous on a wand, however!)

When written in manuscript, the vowels are very often written with short or full strokes rather than notches.

Feda

The twenty principal ogham letters – fifteen representing consonants and five vowels – form four groups of five letters. Each letter is known as a few (from the old Irish fid; pl. feda or fedha) and each group as an aicme.

Each letter is (ostensibly) named for a tree, hence the Celtic tree alphabet. The names, which are acrophonic (i.e., they begin with the letter’s sound), are in an archaic form of Irish and there are many variations (see below). Those in the following table are the official names in Unicode. The table also shows the corresponding trees in English; those marked with an asterisk (*) are uncertain or disputed (see the discussion in Ogham Trees).

Forfeda

The twenty feda are supplemented by the “additional fews” or forfeda, which, as the name suggests, stand apart from the others. The first five forfeda conventionally stand for diphthongs, but are also used for foreign (Greek) consonants.

In fact, Graves’s discussion suggests that this use was foremost, that the diphthongs specify Greek consonants in a rather cryptic way. This seems credible, if only because diphthongs per se could easily have been represented by combinations of individual vowels.

Moreover, the forms of eabhadh, or, and uilleann are clearly angular forms of the Greek consonants chi, theta, and phi. (The similarities between ifin and pi and between eamhancholl and xi are less clear!)

So, how do the Old-Irish diphthongs correspond to the Greek consonants?

χ = ea — Classical Greek χ was pronounced /k^h/ (not /x/) – i.e., an aspirated /k/. But is still pretty well represented by a simple combination of c and h. c is in the e-column and h in the a-column.

θ = oi — Graves calls th a “shrill” d: d is in the o-column and i, Graves says, indicates “shrillness” in Irish. Classical Greek θ was pronounced /t^h/ (not /θ/) – i.e., an aspirated (= “shrill”?) /t/. Why then does Graves say d? Perhaps “shrillness” equates to aspiration and lack of voice… ?

φ = oi — Graves calls ph a “shrill” f: f is in the u-column and, again, i indicates “shrillness”. Classical Greek φ was pronounced /p^h/ (not /ɸ/ or /f/) – a “shrill” p?! Given the discussion for θ, it would be more consistent to say f (/v/ in Old Irish) is a “shrill” φ!

π = ia — p is the unvoiced labial plosive corresponding to the voiced labial plosive b. b is in the a-column and Graves suggests that the preceding i just distinguishes p from b. Why i? Graves doesn’t say. Fancifully, it might be because q is in the i-column, and q is used in Irish where p is used in other Celtic languages such as Welsh (i.e., Goidelic v. Brythonic). Does this credit the ancient Irish with too deep an understanding of comparative linguistics?

(Note, however, that sometimes ifin is given as io rather than ia. Following the line of Graves’s argument, we might say that p is “a form of” t – the phonetic relationship here is that p is the unvoiced labial plosive and t the unvoiced dental plosive – and t is in the o-column.)

ξ = ae — Classical Greek ξ was pronounced /ks/, a simple combination of c and s: c and s are both in the e-column; a is added simply to form a two-vowel combination. Graves suggest that here a stands for a “null” h (h wasn’t used in Old Irish).

There is one futher forfid ―

This – a “flattened” beith, phonetically and graphically – was presumably invented for p in P-Celtic and Pictish inscriptions, maybe because it had been forgotten – or never realised outside bardic circles – that ifin stood for p as well as ia.

Alternative names

Over the centuries, many variations of the ogham letter names have been recorded. Some of these are shown in the right-hand column of the following table (after Everson and others).

Names in capitals are the “official” Irish names where these differ from the English forms: although these are not defined in the Unicode standard, they were included in the original proposal (see Everson).

The third column shows the letter names in Welsh (Cymric) after Matthews. (N.B. These are the corresponding tree names, not necessarily the historical names of the ogham letters in Cymric.)