The origins of manuscript ogam and medieval Irish grammatical tradition

By Deborah Hayden, OG(H)AM’s Co-Investigator

Around the middle of the ninth century, an Irish scribe who was perhaps feeling a little the worse for wear after a long night of merrymaking jotted down the word LATHEIRT (‘excessive drunkenness’, ‘hangover’) in ogam across the upper margin of a page in his copy of Priscian’s Latin grammar. The comment may have been intended as an apology for any shortcomings in his work on transcribing or annotating the popular Latin teaching-text, which circulated widely across Europe throughout the Middle Ages. This particular copy of Priscian’s grammar, which is now preserved in the Abbey Library at St Gall in Switzerland (MS 904), contains nearly 3,500 glosses in Old Irish and is therefore one of the most important sources for our knowledge of the form of the Irish language, as well as of the development of linguistic thought among Irish scholars, at the earliest stages of writing in that vernacular. In addition, however, St Gallen MS 904 is one of the oldest sources attesting to the use of ogam in manuscripts – a phenomenon that would only continue to grow in popularity over the course of the next millennium.

The top portion of a page in the 9th century St Gallen manuscript, which has an ogham word for 'hangover' written in the top margin.
St Gallen, Stiftsbibliothek MS 904, p. 204 (9th century): a copy of Priscian’s Latin grammar with the word LATHEIRT (‘excessive drunkenness, hangover’) written in ogam in the upper margin (Image courtesy of

So-called ‘manuscript’ or ‘scholastic’ ogam is in many respects a distinctive development of the script chiefly used for stone monuments in Ireland, Scotland, Wales and the Isle of Man between the late fourth and seventh centuries. While ogam inscriptions on stone typically served a very functional purpose in marking territorial boundaries or recording funerary memorials, the use of the script in written documents from the eighth century onwards is often closely tied to more theoretical ideas about literacy, foreign languages, cryptography and secret communication that are also attested in many other contemporary linguistic traditions.

Ogam and manuscript marginalia

Rather like the observation of our hungover scribe of the St Gall manuscript, many of the earliest attestations of manuscript ogam are occasional in nature and serve the same purpose as other manuscript marginalia written in Roman script. For example, ogam might be used to note the occurrence of an important feast-day or simply to record the signature of the scribe, as in this page from the early ninth-century Irish manuscript known as the ‘Stowe Missal’ (Royal Irish Academy MS D ii 3):

The scribe has apparently signed their name in ogam as SONID/DINOS in the Stowe Missal.
The scribal signature SONID/DINOS in Dublin, Royal Irish Academy MS D ii 3 (‘The Stowe Missal’, early 9th century). On the background and contents of this manuscript, see this online talk by Lars Nooij, and also his 2021 PhD thesis, available at
(Image courtesy of the Irish Script on Screen project).

In some cases, we even find evidence of multilingual interaction through the medium of ogam. This is demonstrated by the eighth-century manuscript St Gallen, Stiftsbibliothek 11, where one dry-point gloss has been identified as a literal translation of the Latin word itaque into Old High German, using both runes and ogam symbols (for images and discussion, see here).

Ogam and Latin grammatical learning

Other early examples of manuscript ogam occur in tabulations or discussions of alphabets that were transmitted either alongside, or as part of, grammatical teaching-texts. For example, the late-eighth or early-ninth century manuscript Bern, Burgerbibliothek 207 – a collection of Latin grammars thought to have been written at Fleury Abbey in Saint-Benoît-sur-Loire, France – contains a fragment on which seven lines have been written in ogam script. The first of these, although partly obscured by a Latin grammar that was copied over it, evidently consists of ogam symbols written in the order of the Latin alphabet. By contrast, the next six lines feature only the ogam symbols for vowels divided by those for different consonants, with the letters listed in the order of the Latin alphabet rather than the ogam one (e.g. BA BE BI BO BU, CA CE CI CO CU, etc.). It is possible that the scribe of this fragment, which was probably written at the same time as the manuscript in which it is now preserved, intended to create a syllabary to be used as a mnemonic device for learning the ogam script. Whatever be the case, it certainly points to Irish influence at the continental centre of learning in which the Latin grammars found in the manuscript were produced.

A photo of a page of the Burgerbibliothek manuscript from Bern - ogam symbols are put in the order of the Latin alphabet, followed by a syllabary.
Bern, Burgerbibliothek MS 207, fol. 1br: ogam symbols written in the order of the Latin alphabet, followed by an ogam syllabary. A more detailed discussion of this fragment can be found here. (Image courtesy of

Ogam in the earliest grammar of the Irish language

The popularity of ogam in later Irish manuscript tradition owes much to a medieval Irish grammatical text known as Auraicept na nÉces (‘The Scholars’ Primer’). This compilation of teaching material consists primarily of commentary on very rudimentary linguistic concepts such as letters, syllables, metrical units and stylistic devices for use in poetic composition, and its contents are highly indebted to Latin grammatical learning. Parts of the Auraicept have been dated on linguistic grounds to as early as the eighth century, but it is probable that the majority of the text’s glossing and commentary was added between the ninth and twelfth centuries, and the work now only survives in manuscripts of the late-medieval period.

The prologue to Auraicept na nÉces sets out an origin-legend for the Irish language in which it is claimed that, ten years after the dispersal of the languages from the Tower of Babel, the Irish scholar Fénius Farsaid was asked by the school in Egypt to create a language from the best parts of all the languages then in existence – an endeavour that naturally resulted, according to the text’s scholiast, in Goídelc (‘Irish’). This particular spin on the linguistic origin-legend recounted in the biblical Book of Genesis is a fairly typical manifestation of a much broader literary phenomenon whereby medieval Irish scholars attempted to graft their own language and history onto the authoritative framework of biblical narrative. It also had the advantageous implication, however, that Irish did not originate in the sin of pride which led to the building of the Tower, thus serving to establish the superiority of that vernacular over all other languages.

A 16th century painting imagining the collapsed 'Tower of Babel'.
Pieter Bruegel the Elder, ‘The Tower of Babel’ (c. 1563)

The claim made in the prologue to the Auraicept for the linguistic superiority of Irish is reinforced elsewhere in the grammar by the inclusion of ogam symbols and letter-names alongside alphabet tables for Hebrew, Greek and Latin, commonly identified in the medieval period as the tres linguae sacrae (‘three sacred languages’) by virtue of the biblical account of their inscription on the cross of Christ (John 19:19–20). One of the Auraicept’s commentators even went so far as to suggest that not only was the Irish grammarian Fénius Farsaid himself responsible for discovering the alphabets of both the sacred languages and of ogam, but also that ogam was more ‘exact’ than the other three because it was invented last. This explanation is found in a copy of the Auraicept preserved in the ‘Book of Ballymote’ (Dublin, Royal Irish Academy MS 23 P 12), written around the turn of the fifteenth century:

A page from the Book of Ballymote, which shows alphabet tables of Hebrew, Greek and Latin scripts in 'The Scholar's Primer'.
The inclusion of the ogam alphabet in the Book of Ballymote, in the 'Scholar's Primer'.
Dublin, Royal Irish Academy MS 23 P 12 (‘The Book of Ballymote’), fols. 175v–176r (14th–15th centuries): Latin, Greek, Hebrew and ogam alphabets in Auraicept na nÉces, ‘The Scholars’ Primer’ (images courtesy of Irish Script on Screen).

The inclusion of ogam symbols in early discussions of alphabets and grammatical learning may have played a role in the later use of the script for cryptographic purposes. Such a connection is likewise illustrated by the Book of Ballymote, where a copy of Auraicept na nÉces is juxtaposed with a text known as In lebor ogaim (‘The book of ogam’). The latter tract contains over 100 different ‘alphabets’ modelled on ogam script, and seems to have formed part of the educational curriculum of medieval Irish scribes. But this is a topic that merits a whole separate blog post – so please stay tuned for more later this year!


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