The early date would place its oral composition soon after the battle, presumably in the Hen Ogledd ("Old North"); as such it would have originated in the Cumbric dialect of Common Brittonic.

They tell how the ruler of the Gododdin, Mynyddog Mwynfawr, gathered warriors from several Brittonic kingdoms and provided them with a year's feasting and drinking mead in his halls at Din Eidyn, before launching a campaign in which almost all of them were killed fighting against overwhelming odds.

A number of stanzas may open with the same words, for example "Gwyr a aeth gatraeth gan wawr" ("Men went to Catraeth at dawn").

[f]It is a sad wonder to me in what landMarro's only son was slain.Other stanzas praise the entire host, for example number 13:[6] Men went to Catraeth at mornTheir high spirits lessened their life-spanThey drank mead, gold and sweet, ensnaring;For a year the minstrels were merry.Red their swords, let the blades remainUncleansed, white shields and four-sided spearheads,Before Mynyddog Mwynfawr's men.Mead is mentioned in many stanzas, sometimes with the suggestion that it is linked to their deaths.

Several of these features can be seen in stanza 33:[9] Men went to Catraeth with a war-cry,Speedy steeds and dark armour and shields,Spear-shafts held high and spear-points sharp-edged, And glittering coats-of-mail and swords,He led the way, he thrust through armies,Five companies fell before his blades.Rhufawn His gave gold to the altar,And a rich reward to the minstrel.

Others came from further afield, for example one came from "beyond Bannog", a reference to the mountains between Stirling (thought to have been Manaw Gododdin territory) and Dumbarton (chief fort of the Brittonic Kingdom of Strathclyde) – this warrior must have come from Pictland.

One of these is a stanza which celebrates the victory of the Britons of the Kingdom of Strathclyde under Eugein I, here described as "the grandson of Neithon", over Domnall Brecc ("Dyfnwal Frych" in Welsh), king of Dál Riata, at the Battle of Strathcarron in 642:[14] I saw an array that came from Kintyre[i]who brought themselves as a sacrifice to a holocaust.I saw a second [array] who had come down from their settlement,who had been roused by the grandson of Neithon.I saw mighty men who came with dawn.And it was Domnall Brecc's head that the ravens gnawed.Another stanza appears to be part of the separate cycle of poems associated with Llywarch Hen.

[17] If the poem was composed soon after the battle, it must predate 638, when the fall of Din Eidyn was recorded in the reign of Oswy king of Bernicia, an event which is thought to have meant the collapse of the kingdom of the Gododdin.

[19] Most of the debate about the date of the poem has employed linguistic arguments, mostly concerning rhyme (since more is known about early Welsh phonology than other aspects of the language, like syntax).

[20] Kenneth H. Jackson concluded that the majority of the changes that transformed British into Primitive Welsh belong to the period from the middle of the 5th to the end of the 6th century.

If the poem dates to this time, it would have originated in an early form of Cumbric, the usual name for the Brittonic speech of the Hen Ogledd.

[23] Ifor Williams, whose 1938 text laid the foundations for modern scholarly study of the poetry, considered that part of it could be regarded as being of likely late 6th-century origin.

[25] Jackson however considers that there is "no real substance" in these arguments, and points out that the poetry would have been transmitted orally for a long period before being written down, and would have been modernised by reciters, and that there is in any case nothing in the language used which would rule out a date around 600.

Koch, reviewing the arguments about the date of the poetry in 1997, states:[27] Today, the possibility of an outright forgery – which would amount to the anachronistic imposition of a modern literary concept onto early Welsh tradition – is no longer in serious contention.

Rather, the narrowing spectrum of alternatives ranges from a Gododdin corpus which is mostly a literary creation of mediaeval Wales based on a fairly slender thread of traditions from the old Brittonic North to a corpus which is in large part recoverable as a text actually composed in that earlier time and place.Koch himself believes that a considerable part of the poem can be dated to the 6th century.

"[31] Likewise, Patrick Sims-Williams concluded in 2016 that, 'evaluating the supposed proofs that poems in the Books of Aneirin and Taliesin cannot go back to the sixth century, we have found them either to be incorrect or to apply to only a very few lines or stanzas that may be explained as additions.

Apart from the Gododdin, the kingdom of Alt Clut occupied the Strathclyde area and Rheged covered parts of Galloway, Lancashire and Cumbria.

The Gododdin, known as the Votadini in the Romano-British period, occupied a territory from the area around the head of the Firth of Forth as far south as the River Wear.

Gwenogvryn Evans in his 1922 edition and translation of the Book of Aneirin claimed that the poem referred to a battle around the Menai Strait in 1098, emending the text to fit the theory.

He feasted them at Din Eidyn for a year, then launched an attack on Catraeth, which Williams agrees with Stephens in identifying as Catterick, which was in Anglo-Saxon hands.

[40] The battle at Catraeth has been seen as an attempt to resist the advance of the Angles, who had probably by then occupied the former Votadini lands of Bryneich in modern north-eastern England and made it their kingdom of Bernicia.

He draws attention to a poem in Canu Taliesin entitled Gweith Gwen Ystrat ('Battle of Gwen Ystrat'):[44] The men of Catraeth arise with the dayaround a battle-victorious, cattle-rich sovereignthis is Uryen by name, the most senior leader.There is also a reference to Catraeth in the slightly later poem Moliant Cadwallon, a panegyric addressed to Cadwallon ap Cadfan of Gwynedd, thought to have been composed in about 633.

[45] He considers that, in view of the references in the three poems, there is a case for identifying the attack on Catraeth recorded in Y Gododdin with the Battle of Gwen Ystrat.

He points out that according to the Historia Britonnum it was Rhun, son of Urien Rheged who baptized the princess Eanflæd of Deira, her father Edwin, and 12,000 of his subjects in 626 or 627.

A colour facsimile edition of the manuscript with an introduction by Daniel Huws was published by South Glamorgan County Council and the National Library of Wales in 1989.

In English, Y Gododdin was a major influence on the long poem In Parenthesis (1937) by David Jones, in which he reflects on the carnage he witnessed in the First World War.

Another poet writing in English, Richard Caddel, used Y Gododdin as the basis of his difficult but much-admired poem For the Fallen (1997), written in memory of his son Tom.

The theme and rhythm of Y Gododdin are also the undercurrent for Owen Sheers's Pink Mist (2012),[51] an epic elegy to dead and wounded soldiers who served in Afghanistan; the poem, which drew on 30 interviews with returned servicemen, was originally commissioned for radio and then produced by the Old Vic theatre company as a stage play.

[52] The poem has also inspired a number of historical novels, including Men Went to Cattraeth (1969) by John James, The Shining Company (1990) by Rosemary Sutcliff, and The Amber Treasure (2009) by Richard J Denning.

This was a collaboration with the Welsh avant-garde theatre company Brith Gof and was performed in Wales, Germany, Italy, the Netherlands, and Scotland.