Welsh-language literature () has been produced continuously since the divergence of Welsh as a distinct language from Brittonic in around the 5th century AD up to the present day.Huws Daniel National Library of Wales and Centre for Advanced Welsh and Celtic studies. 2022. A Repertory of Welsh Manuscripts and Scribes c. 800 – c. 1800. Aberystwyth: National Library of Wales and the Centre for Advanced Welsh and Celtic Studies. The earliest Welsh literature is poetry, which in its very earliest examples shows many of the features of what became known as cynghanedd or the strict metres; and for most of the history of Welsh literature poetry has been held in higher regard than prose.Williams, Gwyn (1953) An Introduction to Welsh Poetry, London: Faber & Faber.John Rowlands (1992) Ysgrifau ar y Nofel, Cardiff: University of Wales Press. p2 (in Welsh)R. M. Jones (1998) ‘The Present Situation’ in Johnston, Dafydd [ed] (1998) A Guide to Welsh Literature c.1900–1996, Cardiff: University of Wales Press, p277. Poetry makes up the larger part of the surviving corpus of Welsh literature from the period prior to the 19th century; nevertheless prose has also been written in Welsh since at least the 11th century. Today, readers and students of Welsh literature can draw on sixteen centuries of writing across all major literary genres in a vibrant, living tradition.

Welsh-language literature has played a major part in the self-assertion of Wales and its people,Morgan, Prys (1983) 'From a Death to a View: The Hunt for the Welsh Past in the Romantic Period.' in Eric Hobsbawm & Terence Ranger (eds.), The Invention of Tradition. Cambridge University Press, 1983. having provided a focal point for a sense of national identity through a long period during which Wales had no form of political or administrative independence.Williams, Gwyn A. (1985) When Was Wales? A History of the Welsh. Penguin, pp. 40–45 The Welsh national anthem describes Wales as "Gwlad beirdd a chantorion" ('A land of poets and singers') and "Paradwys y bardd" ('The poet's paradise'). It has been suggested that literature, and poetry in particular, has retained a greater relative prominence in Welsh-language culture than in other cultures of Britain and Ireland, and historically both publishing and readership in Welsh has belied its status as a minority language, and significantly exceeded that seen in other Celtic languages even when Welsh was spoken by fewer people.C. A. Charnell-White (2025), 'Print and the Celtic Languages: Publishing and Reading in Irish, Welsh, Gaelic, and Breton, 1700–1900', Welsh History Review, 32:3Niall Ó Ciosáin (2021) 'The language of the printing-house: why so many books in Welsh and Scottish Gaelic were printed in 18th-century Ireland, and so few in Irish', Folk Life, 59(1), 36–51. This vibrancy continues today. Its centrality to the national consciousness is evidenced by the size and enthusiasm of the audiences attending the annual National Eisteddfod of Wales (Eisteddfod Genedlaethol Cymru), which grew out of a long-standing tradition of literary competitions to become probably the largest amateur arts festival in Europe.

Middle Ages

It has been suggested that the earliest surviving literature in Welsh represents a direct continuation of a tradition of panegyric and storytelling which was already present in the pre-Roman and pre-Christian Celtic culture of Iron Age Britain. Though this would have been an oral tradition and none of its literary products have survived, Roman accounts of Celtic cultures in Britain and adjacent areas such as Ireland and Gaul point to a long-established social and political function for the Bard or poet (Welsh bardd – the concepts are not distinct in Modern Welsh) possibly overlapping somewhat with that of the Druid: they would be attached to figures of political authority to serve as propogandists on their behalf, as well as being repositories for indigenous learning. These inferences are borne out by the fact this function appears to be already well established in the earliest Welsh literature.

Because the earliest literature that might reasonably be called Welsh rather than Brittonic or Celtic would still have been entirely oral, that which has survived represents only those examples and fragments which were written down. The surviving manuscripts are in many cases likely to be copies of earlier manuscripts now lost, and may have been produced some time after the works they contain would have been originally composed. Dating the earliest Welsh literature with any precision is thus fraught with difficulty: the extent to which these texts can or should be accepted as genuine examples of literature from the earliest periods relies on linguistic and other evidence. In many cases differences in language support an earlier origin, but definitive claims as to age remain somewhat speculative; and even when a text may plausibly attributed in the main to an earlier period later modifications and additions cannot be ruled out. Similar difficulties affect many other vernacular European literatures, such as that of Irish,Stifter, D. (2024) ‘The dawn and twilight of Old Irish scholarship’, Language & History, 67(3), pp. 185–206. and to a greater or lesser degree apply to most of the major Welsh texts of the medieval period, including the Mabinogion.

The earliest known examples of written Old Welsh are marginalia, such as the Surexit memorandum in Latin manuscripts such as the Juvencus Manuscript.Peter Lord (2003) Medieval Vision: The Visual Culture of Wales. Cardiff: University of Wales Press. p.25 Besides these early fragments, approximately 80 manuscripts entirely or substantially in Welsh have survived from the medieval period, all of which were produced during the 13th–15th century. Perhaps the most important are those sometimes referred to as the Four Ancient Books of Wales: Llyfr Du Caerfyrddin (The Black Book of Carmarthen) Llyfr Taliesin (The Book of Taliesin) Llyfr Aneirin (The Book of Aneirin) Llyfr Coch Hergest (The Red Book of Hergest) which between them contain most of the major literary works of the medieval period in Welsh. None of these books was produced earlier than the 13th century, however it is accepted that much of their contents is likely to be considerably older.

If common estimates for the original composition of key texts are accepted, then the oldest Welsh literature has can be dated to the 6th century. Two sets of englynion written in the 9th century, part of the marginalia of the Latin Juvencus Manuscript, are usually accepted to be the earliest-written example of Welsh literature.John T. Koch, 'The Juvencus Manuscript', in Celtic Culture: A Historical Encyclopedia, ed. by John T. Koch (Santa Barbara: ABC-CLIO, 2005), s.v.

Welsh poetry of the mediaeval period is usually divided into three chronological stages. The first is that of the Cynfeirdd ('Early Poets'), covering poetry from the 6th to 11th centuries; this was followed by the period of Beirdd y Tywysogion ('The Poets of the Princes') or Gogynfeirdd (lit. 'Somewhat Early Poets') in the 12th and 13th centuries; and finally Beirdd yr Uchelwyr, ('The Poets of the Nobles') from the 14th century to the early part of the 16th. Additionally, storytelling practices were continuous throughout the Middle Ages in Wales; the surviving body of medieval Welsh prose literature (in the form of the Mabinogion) is generally believed to date to the period straddling the first two of these poetic periods.Sims-Williams, Patrick, 'The Submission of Irish Kings in Fact and Fiction: Henry II, Bendigeidfran, and the dating of the Four Branches of the Mabinogi', Cambridge Medieval Celtic Studies, 22 (Winter 1991), 31–61.

Early poets (Cynfeirdd), 6th–10th centuries

An interesting feature of much of the earliest Welsh poetry is that it was produced outside modern day Wales in areas that are now part of England and Southern Scotland. The earliest of the Cynfeirdd are associated with the area now referred to as Yr Hen Ogledd ('the 'Old North'), now Cumbria and Southern Scotland, and the language of this area time has sometimes been described as being Brittonic (a precursor to Modern Welsh), though is usually now characterised as Old Welsh and/or Cumbric. It is clear that there was considerable cultural transfer between modern Wales and this area even after the expanding Kingdom of Northumbria cut them off from one another. The names Taliesin and Aneirin are among five names mentioned by Welsh monk Nennius in the 9th century Latin Historia Brittonum as the greatest of the Britons' poets during the sixth century; and they are the earliest two plausibly historical figures to whom specific surviving texts are attributed. No surviving work can similarly be associated with the three other poets mentioned by Nennius, but later works from the 9th and 10th centuries are also considered part of the Cynfeirdd period, many anonymous but others incorrectly attributed to Aneirin or Taliesin or to characters such as Myrddin and Llywarch Hen.

Aneirin

The dominant theme of the earliest Welsh poetry is the panegyric: heroic, it serves to celebrate and commemorate heroes of battle and military success. This is the case with Y Gododdin, which, allowing for the chronological issues outlined above, may be the earliest surviving literary work in Welsh. The work, constituting about a thousand lines of poetry, centres around the c.570 Battle of Catraeth (usually associated with Catterick) in which the eponymous 'Hen Ogledd' kingdom suffered a calamitous defeat against an unspecified foe (often assumed to be a neighbouring Anglo-Saxon kingdom, though this is not explicit in the text itself). Aneirin's perspective as a poet as presented in work is as an active participant in the battle himself. Though often referred to as an epic Y Gododdin is not strictly speaking a narrative work, consisting instead of a series of verse elegies, either to individual warriors killed in the battle or to the host as a whole. Although the battle is clearly depicted as a disastrous defeat in which the whole host is slaughtered, the tone is broadly valedictory and has been described as "unique in Welsh literature in that it is the only work that gives the heroic view of life full and unfettered expression, undiluted by other concepts". Although the work was forgotten after the end of the Middle Ages until its rediscovery in the 18th century, its literary value has long been recognised with numerous editions, translations and adaptations made. Although its form as a series of elegies deprives it of much sense of narrative and limits the range of ideas expressed, "it employs an immense variety of words, expressions, phrase and sentence formations, rhythms and metrical devices and even of imagery... the great verbal richness of the Gododdin cannot fail to astonish". Despite its heroic character, the often graphic depictions of violence and its aftermath have inspired many decidedly unromantic poetic treatments of conflict in later periods.Jarman (1998), p. lxxxvi. Although an important and valuable work in its own right, Y Gododdin also contains what is usually interpreted as a passing reference to King Arthur, which if original makes it the earliest literary reference to the figure in any language; though it is impossible to definitively prove that this is a genuine 6th century element rather than a later addition.

Taliesin