In 934 Athelstan, quite probably the first king of England proper, had attacked Scotland and Strathclyde, three years later Constantine III king of Scotland and Owain map Dyfnwal king of Strathclyde responded by uniting with Olafr Gothfrithson (or Anlaf) king of Dublin and leading their combined forces against Athelstan.

The opposing forces met at the Battle of Brunanburh, where Athelstan won a famous victory; Eochain the Bald was killed together with another four northern 'kings' and severn Irish earls from Olaf's army. It was one of the defining moments in the history of England; according to Winston Churchill it was one of the three battles to which the English owed their existence as a nation. One might argue that one battle was neither here nor there, but it certainly retains a symbolic significance as the first military victory of an English as opposed to Anglo-Saxon king.

The exact location of the battle is not known. The twelfth century chronicler Florence of Worcester placed it near the river Humber, but it was most likely fought somewhere in northwestern England or southwestern Scotland, along the Solway Firth.

The battle was the subject of an early English poem, known naturally enough as "The Battle of Brunanburh". The poem is recorded in four manuscript copies of The Anglo-Saxon Chronicle, and in fact serves as the entry for the year 937, although it is entirely unclear as to whether the poem was written specifically for the The Anglo-Saxon Chronicle, or an entirely independent work that was simply incorporated into later manuscript copies of the Chronicles.

The poem was originally written in Anglo-Saxon, or Old English if you prefer, a language quite unintelligible to the modern ear, hence the following is the text of Alfred Lord Tennyson's 1876 translation into something approaching Modern English. (Incidentally the reference to Welshmen at the end refers to the Strathclyde 'Welsh', rather than the Welsh 'Welsh' who were not present at the battle.)

Athelstan King,
Lord among Earls,
Bracelet-bestower and
Baron of Barons,
He with his Brother,
Edmund Atheling,
Gaining a lifelong
Glory in battle,
Slew with the sword-edge
There by Brunanburh,
Brake the shield-wall,
Hew'd the linden-wood,
Hack'd the battle-shield,
Sons of Edward with hammer'd brands.
Theirs was a greatness
Got from their grand-sires
Theirs that so often in
Strife with their enemies
Struck for their hoards and their hearths
and their homes.
Bow'd the spoiler,
Bent the Scotsman,
Fell the ship-crews
Doom'd to the death.
All the field with blood of the fighters
Flow'd, from when the first the great
Sun-star of morning-tide
Lamp of the Lord God
Lord everlasting,
Glode over earth till the glorious creature
Sank to his setting.
There lay many a man
Marr'd by the javelin,
Men of the Northland
Shot over shield.
There was the Scotsman
Weary of war.
We the West-Saxons,
Long as the daylight
Lasted, in companies
Troubled the track of
the host that we hated;
Grimly with swords that were sharp
from the grindstone,
Fiercely we hack'd at the flyers before us.
Mighty the Mercian,
Hard was his hand-play,
Sparing not any of
Those that with Anlaf,
Warriors over the
Weltering waters
Borne in the bark's-bosom
Drew to this island
Doom'd to the death.
Five young kings put asleep by the sword-stroke,
Seven strong earls of the army of Anlaf
Fell on the war-field, numberless numbers, Shipmen and Scotsmen.
Then the Norse leader
Dire was his need of it,
Few were his following
Fled to his war-ship;
Fleeted his vessel to sea with the king in it,
Saving his life on the fallow flood.
Also the crafty one,
Crept to his North again,
Hoar-headed hero!
Slender warrant had
He to be proud of
The welcome of war-knives
He that was reft of his
Folk and his friends that had
Fallen in conflict,
Leaving his son too
Lost in the carnage,
Mangled to morsels,
A youngster in war!
Slender reason had
He to be glad of
The clash of the war-glaive
Traitor and trickster
And spurner of treaties
He nor had Anlaf
With armies so broken
A reason for bragging
That they had the better
In perils of battle
On places of slaughter
The struggle of standards,
The rush of the javelins,
The crash of the charges,
The wielding of weapons
The play that they play'd with
The children of Edward.
Then with their nail'd prow
Parted the Norsemen, a
Blood-redden'd relic of
Javelins over
The jarring breaker, the deep-sea billow,
Shaping their way toward Dyflen again,
Shamed in their souls.
Also the brethren,
King and Atheling,
Each in his glory,
Went to his own in his own West-Saxonland,
Glad of the war.
Many a carcase they left to be carrion,
Many a livid one, many a sallow-skin
Left for the white-tail'd eagle to tear it, and
Left for the horny-nibb'd raven to rend it, and
Gave to the garbaging war-hawk to gorge it, and
That gray beast, the wolf of the weald.
Never had huger
Slaughter of heroes
Slain by the sword edge
Such as old writers
Have writ of in histories
Hapt in this isle, since
Up from the East hither
Saxon and Angle from
Over the broad billow
Broke into Britain with
Haughty war-workers who
Harried the Welshman, when
Earls that were lured by the
Hunger of glory gat
Hold of the land.