Ogham is a real alphabet. It was cut into the edges of standing stones across Ireland and western Britain, mostly between about the fourth and seventh centuries, and most surviving inscriptions say something like X son of Y: memorials and territorial markers.

The tree associations are real too, or at least the medieval Irish literary tradition is real, and some of it is genuinely beautiful.

The tree calendar is not real. Thirteen months, a birth tree, a lunar zodiac running from 23 December. That was invented in 1948 by an English poet, and almost every Ogham book and deck you can buy is downstream of it.

I want to set out what is actually there, because what is actually there is better.

The alphabet

Twenty letters in the primary alphabet, arranged in four groups of five, called aicmí. A later addition of five more, the forfeda, brings it to twenty-five.

The letters are strokes cut across or beside a central line, the droim or stemline, which on a standing stone is usually the edge of the stone itself. You read from the bottom upwards.

All the letter names below are Old Irish, not Scottish Gaelic. Where a name resembles a modern Scottish Gaelic tree name, that is common descent rather than identity.

The alphabetical order is Beith, Luis, Fearn, Sail, Nion, giving the whole system its traditional name, the beith-luis-nin after the first letters. Note that: modern scholarship gives Beith-Luis-Fearn as the order, while the older reading gave Beith-Luis-Nion, and that discrepancy matters later.

The medieval sources

Everything we know about the meaning of the letter names comes from a small body of Irish manuscript material.

  • Auraicept na n-Éces, the Scholars' Primer. A grammatical tract surviving in the Book of Ballymote, around 1391, and the Yellow Book of Lecan, claiming to derive from seventh century sources. Edited by George Calder in 1917.
  • In Lebor Ogaim, the Book of Ogam or Ogam Tract, which sits immediately before the Auraicept in the Book of Ballymote. It describes the alphabet, its variants and the kennings.
  • De dúilib feda na forfed, on the supplementary letters. The Auraicept attributes the invention of Ogham to Ogma, champion and poet of the Tuatha Dé Danann. In its own words the father of Ogham is Ogma and the mother of Ogham is Ogma's hand or knife. The first thing ever written in Ogham, in that tradition, was seven strokes of beithe on a birch rod, sent as a warning to Lug about his wife.

The kennings: the genuinely good material

Here is what almost nobody uses, and it is the best thing in the entire tradition.

  • The Bríatharogam, word-ogham, is a set of two-word poetic kennings explaining each letter name. Three lists survive from the Old Irish period, attributed to Morann mac Moín, Mac ind Óc and Cú Chulainn. Damian McManus edited and translated them in Ériu in 1988, and his versions are the standard.

They read like this:

  • Beithe, birch. Féochos foltchain, withered foot with fine hair. Glaisem cnis, greyest of skin. Maise malach, beauty of the eyebrow.
  • Luis, flame or herb. Lí súla, lustre of the eye. Carae cethrae, friend of cattle. Lúth cethrae, sustenance of cattle.

Three kennings per letter, from three different authorities, sometimes agreeing and sometimes not. Not definitions. Riddles.

If you want to divine with Ogham, these are your material. They are old, they are attested, they are strange, and they are far richer than any modern keyword list, precisely because they do not resolve neatly.

The tree problem

Here is the correction that changes everything. Most Ogham letters are not tree names.

Later medieval scholars believed they all were and worked backwards, glossing every letter with a plant name to make the system come out even. Modern scholarship, McManus in particular, has shown that at most eight of the twenty letter names are actually trees. Only five are considered comprehensible as tree names by the Auraicept without further glossing.

Luis means flame or herb, not rowan. The kennings themselves support this: friend of cattle and sustenance of cattle are not obviously about a rowan tree.

So the tree Ogham is one interpretive layer, applied medievally, over an alphabet whose letter names mean various things. It is a real tradition and it is worth having. It is just not the bedrock, and it is not druidic.

There is also not one Ogham. The Auraicept lists around a hundred variant systems: a bird ogham, a colour ogham, an agricultural ogham, and many more. The tree list is famous because Robert Graves made it famous, not because it was ever primary.

Robert Graves and The White Goddess

In 1948 the poet Robert Graves published The White Goddess, and modern Ogham has never recovered.

Graves proposed that the Ogham letters formed a calendar of tree magick, each letter ruling a lunar month.

The problems, in order:

  • He used a distorted letter order taken from Roderic O'Flaherty's seventeenth century Ogygia, not the attested order.
  • He built a thirteen-month year beginning on 23 December, a date with no place in any attested Irish calendar. It appears in Graves because it is the traditional day of the year and a day in early courts of law, which is not a calendrical argument.
  • He was working without the Old Irish and without the scholarship on letter ordering.
  • His own grandfather, Charles Graves, was a genuine specialist in the Irish alphabet, and did not agree with him.

Peter Berresford Ellis published a detailed refutation in 1997. Damian McManus's A Guide to Ogam (1991) remains the standard scholarly treatment and contains no tree calendar because there is no tree calendar.

None of which makes The White Goddess worthless. It is a magnificent book of poetic imagination and it has been genuinely generative for a lot of people, including me at seventeen. It is simply not history, and it should never have been read as history.

Your birth tree is not a Celtic tradition. It is 1948. If you use it, use it knowing that.

Using Ogham honestly

You can absolutely work with this. Here is how I would do it.

  • Make your own set. Twenty staves, or twenty-five with the forfeda. Cut from fallen wood, asked for first. Traditionally a single wood, and birch has the strongest claim given the beithe story. Cut the strokes with a knife rather than burning or printing them.
  • Learn the letter names and the kennings, not keywords. Use McManus. Three kennings per letter gives you a three-way reading built into the system, and the ambiguity is the point.
  • Read them as language. Ogham is an alphabet before it is anything else. Drawing letters that spell something is not a coincidence to be explained away, it is the tool doing what it was made for.
  • Cast rather than draw, if you want the older feel. Ogham divination is referenced in Tochmarc Étaíne, where wands of yew are cut and inscribed.
  • Say the names aloud. The kennings are oral poetry and they behave differently in the mouth than on the page.
  • Note the Scottish situation honestly. Ogham inscriptions do occur in Scotland, notably Pictish examples, and several remain undeciphered because the language behind them is not securely known. Ogham is not straightforwardly a Scottish tradition, it is an Irish one that reached here, and the Pictish material is its own unresolved problem.
  • And when you write about it, say which layer you are on. Alphabet: fourth century onwards, epigraphic. Kennings: Old Irish, manuscript. Tree list: medieval gloss. Calendar and birth trees: Robert Graves, 1948.

Four layers, four different levels of authority. Most books collapse them into one and present the newest as the oldest.

Sources

  • McManus, D. (1991). A Guide to Ogam. Maynooth Monographs 4, An Sagart. The standard modern scholarly treatment. Internet Archive record.
  • McManus, D. (1988). Irish letter-names and their kennings. Ériu, 39, 127–168. The definitive edition and translation of the Bríatharogam.
  • Calder, G. (ed. and trans.) (1917). Auraicept na n-Éces: The Scholars' Primer. J. Grant, Edinburgh. Available via Internet Archive.
  • In Lebor Ogaim (the Ogam Tract), Book of Ballymote, c. 1391.
  • Bríatharogam — Wikipedia, carrying McManus's normalised Old Irish kennings with translations in full. Unusually good, and the fastest way to get the three lists side by side.
  • Ogham — Wikipedia, for the alphabet, the aicmí and the inscription corpus.
  • Graves, R. (1948). The White Goddess. Faber. Read it as poetry.
  • Ellis, P. B. (1997). Refutation of the Graves tree calendar. See Ogham and the Tree Alphabet for a summary of the fabrication.
  • Eastwood, L. A Re-evaluation of the Ogham Tree List — Order of Bards, Ovates and Druids. A practitioner working through the discrepancies honestly.
  • Ogham in 3D — Dublin Institute for Advanced Studies, three-dimensional scans of inscribed Ogham stones. Extraordinary and free.

Related: [How to Read an Esoteric Claim]; [Liminal Plants]; [Naming and Speaking]