England is burning. The Great Heathen Army have pillaged and burned their way across the Anglo-Saxon Kingdoms – but their intention is not mere plunder. They’re here to conquer. The Kings of Northumbria and East Angia have already fallen in battle to the Vikings, with local puppets put in their places as little more than tax collectors. Now, the Great Heathen Army will go for broke: they’ll attack the remaining two Kingdoms, and for a brief moment they’ll be masters of all of England. But their success will not last: the brilliance of a young King, Alfred of Wessex, and the exhaustion of the Danish leader Guthrum, will tame them – concluding the war with a surprise baptism, and the partition of the English world between Dane and English. The relationship between King Alfred and Guthrum marks the end of the Viking invasions of England. For now.

There are no contemporary images made of Alfred the Great – the closest we can get are contemporary coins, like this one, minted in his image. (via Wikimedia Commons)

We saw in our previous article the Great Heathen Army commanded by a triumvirate of three ‘brothers’, Ivar the Boneless, Ubba and Halfdan Ragnarsson, sons of the legendary Viking king Ragnarr Loðbrók. The Army is currently overwintering in East Anglia in the winter of 869/70, having killed King Edmund and placed a puppet on his throne. Our sources are chaotic and confused in this era, reflecting the fragmentation of the Kingdom and the social collapse it entails – but it is here that the triumvirate fragments. Ivar the Boneless disappears from the English record after the death of King Edmund – some sources claim that he died in the same year as Edmund, but most historians identify Ivar with the Viking King of Dublin Ímar, where he may have ruled for another four years. Ubba also vanishes for now – although he makes a possible reappearance at the end of the Great Heathen Army’s spectacular run. For now, we will focus on the final brother, Halfdan Ragnarsson.

The Great Summer Army

By now, word of the spectacular successes of the Vikings in England must have spread back homeward, because in the summer of 871 CE, a second wave of Scandinavians crossed the North Sea to England: known to history as the Great Summer Army. This time, they could land unopposed in Viking East Anglia – and their leaders Bagsecg and Guthrum were welcomed with open arms by Halfdan. We know nothing of Bacsegc, although he was apparently the senior commander his origins are obscure – whilst Guthrum was the nephew of King Horik II of Denmark, himself a failed candidate for the throne, doubtless looking to make his fortune on new shores. Together, Halfdan, Bagsecg and Guthrum began planning a campaign to end the war once and for all – by knocking out the only opponent who could pose a real threat to their plans: the West Saxons.

Guthrum, nephew to the King of Denmark, arrived with the Great Summer Army in 871 CE. Modern illustration. (via History of War)

But even with fresh reinforcements, things did not go according to plan. Invading in 870 CE, the Vikings probed the West Saxon defenses over and over – but they were repeatedly thrown back. Perhaps Halfdan was not as able a commander as when he was advised by his brothers – or perhaps the West Saxons were simply far better organized than the other Kingdoms. Fighting reached a fever pitch in the winter of 870/1, with the Vikings making a concerted push toward the West Saxon heartland. Defeated at Reading, the West Saxons under King Æthelred’s brother Alfred drew back to a place named Ashdown in early January. There, they fought a desperate defensive action, holding out long enough for the King’s relief army to arrive. The King caught the Vikings by surprise (as might have been the plan all along), inflicting a heavy defeat upon the Great Heathen Army. The Viking commander Bagsecg, alongside five Viking jarls, were killed in the melee.

The Rise of Alfred; The Fall of Burgred

Although the West Saxons failed to reverse the Viking gains and dislodge them from Reading, the Vikings had been sorely depleted by their invasion. Shortly after Easter 871, exhausted King Æthelred died of natural causes, having vigorously defended Wessex for five years. He was only in his mid-20s, and he was succeeded by his younger brother Alfred, who was only 22 years of age. Newly crowned and eyeing a shaky Kingdom rocked by the Viking invasion, King Alfred opted to sue for peace, ceding the Vikings their conquests in his territory – for now.

A modern composite illustration of the fortified Viking encampment at Repton, 874 CE. (via The Conversation)

The death of Æthelred and the accession of Alfred to the West Saxon throne left only one Anglo-Saxon King who had ruled from before the Viking invasion: King Burgred of Mercia, enjoying (or at least, surviving) his twenty-second year on the throne. But that was about to end. As with East Anglia the year before, the separate peace between the West Saxons and the Norse would mean disaster for the Mercians. The Vikings swiftly returned north to put down a rebellion in Northumbria against their puppet-king Ecgberht, and then turned their full might against Mercia. Overwintering at Repton (modern Derbyshire) in 874 CE, the Viking invasion was brutal and swift. Rather than dying a heroic but ultimately pointless death on the battlefield, pious King Burgred was driven into exile, and according to the Anglo-Saxon Chronicle, he spent his remaining years in Rome. In his place, the Vikings installed Ceolwulf, a handy Mercian noble (who probably had the useful added legitimacy of royal blood) as a puppet king. Three down, one to go.

The Army Splits

Our sources for this period of the Great Heathen Army improve somewhat – if only from the perspective of the Anglo-Saxons. Alfred’s subsequent legitimacy as a West Saxon (and, later, English) King would stem partly from his success in containing the threat posed by the Vikings, and so his official histories and biographies pay much greater attention to it now that he is involved. The writer of onesuch biography, the Welsh monk Asser, tells us that the Great Heathen Army split in 874 after the conquest of Mercia. A part went north with Halfdan, in fight against the Picts and Britons in the Scottish Lowlands, and to begin in earnest the process of turning York from a conquered enemy capital into a permanent Viking city – Asser records Halfdan as handing out lands and titles to his jarls and warriors to formally seed the land with his people. The other part, under the leadership of Guthrum, continued the fight against the West Saxons.

A New Kind of War

But the fight was now of an altogether different nature. Young King Alfred of Wessex was determined not to risk disaster twice. He used the opportunity afforded by the separate peace of 871 to roll out a revolutionary new system of defenses, which would end the threat from the Great Heathen Army once and for all: the burh system. Previous Kings had relied largely upon the traditional forms of Anglo-Saxon warfare in combatting the Vikings: when they hear of raiders, they call their thegns and raise a fyrd, which might take several days or even weeks, and if the raid was small enough to have left beforehand, then it wasn’t an issue – or if it was large enough to still be around, then they could deal with it.

King Alfred of Wessex began constructing a network of burhs – fortified towns that could respond quickly to Viking incusions. Modern illustration. (via The Dockyards)

However, this system had led to complete disaster for three Anglo-Saxon Kingdoms: the fyrd was slow, and staffed by untrained and ill-equipped farmers – utterly insufficient to deal with a mobile and well-equipped Viking army. The West Saxons had held the Vikings at bay mostly through luck, the exceptional talents of their commanders, and by happening to be the wealthiest Kingdom in England. King Alfred now began constructing a network of burhs – fortified settlements, many of which were based on crumbling Roman fortresses or ancient Iron Age hillforts, which would have their own garrison of semi-permanent soldiers, with arms and equipment close at hand. These burhs could respond quickly and in much greater force than whatever levies a reeve could raise from the local farms, and they could be drawn together into a fyrd much more efficiently if a field army was required.

Disaster at Chippenham

Guthrum was now faced with a far better organized and armed enemy than the three brothers had been faced with a decade previously. The Vikings were forced to move much more slowly through West Saxon territory, their foragers and scouts beset by ambushes from local burhs, and they had to occupy fortified positions where they could. Penned into the town of Wareham, Guthrum eventually drew up a truce to leave West Saxon land – and King Alfred drew a sigh of relief. He knew that the Vikings could not be bought off permanently – but more time would give him an opportunity to extend the burhs and regroup. Withdrawing to his estates at Chippenham, King Alfred took a rare opportunity to rest. But as he celebrated the New Year of 878, he received terrible news: the Vikings had broken their truce, and were imminently upon his. Guthrum had stormed across Wessex with all possible haste to catch the King unawares, and Ubba (now re-entering the historical record) had sailed up the Severn and attacked from the West. Caught between hammer and anvil, without enough time to summon the fyrd, King Alfred made the only decision he could: he abandoned his Kingdom, and fled into the marshes.

An 1801 monument marks the location of the fortified monastery at Athelney where King Alfred based his resistance to the Viking occupation of Wessex. Nearby archaeological excavations have revealed one of the only known Anglo-Saxon metalworking sites. (via Wikimedia Commons)

With the Kingdom of Wessex now leaderless, Guthrum wasted no time in mopping up the resistance to the Great Heathen Army. In fourteen years, the Vikings had deposed every single one of the four Anglo-Saxon Kings of England, forging a network of client kingdoms that stretched from the Scottish Lowlands, to the heathlands of Dartmoor. But there is a reason that we do not talk of the ‘Viking conquest of England’. Unlike the other Kings of the Anglo-Saxons, Alfred was neither killed in battle like Ælla or Edmund, nor did he flee into exile like Burgred of Mercia. From his stronghold in the marshes at Athelney, King Alfred waged a guerilla war against Guthrum, conducting hit-and-run raids, patiently building up a mass resistance to the Vikings. Finally, he was ready to meet them in battle. He summoned his loyalists to Egbert’s Stone at Brewham in Somerset, and set out to meet the Vikings head-on.

Victory at Edington

Guthrum was not afraid to give battle, and probably relished this opportunity to put down the West Saxon rebels once and for all. The two armies met at Eðandun (modern Edington, Wiltshire), where, against all odds, the West Saxons resoundingly smashed the Viking invaders. The existing historical sources are infuriatingly vague: how was this military feat possible? The Anglo-Saxon Chronicle hints that King Alfred and the West Saxons were “Fighting ferociously, forming a dense shield-wall against the whole army of the Pagans”. The Vikings broke in confusion, and Alfred took no chances, grabbing this opportunity to comprehensively scatter the Vikings. The West Saxons pursued the Vikings for fourteen days, according to the sources, eventually bottling them up in ‘a fortress’, probably the town of Wareham.

The Anglo-Saxon shield wall was critical in their victory at the Battle of Edington. Modern illustration. (via X/Twitter)

There, the West Saxons systematically besieged the town, removing all sources of food in order to starve the Danes out – a significant feat in an era where siege warfare was barely known. Whilst the West Saxons were busy pursuing Guthrum, news of a further disaster for the Vikings reached them. Halfdan’s ‘brother’ Ubba, former triumvir of the Great Heathen Army, had landed at the fortress of Cynwit (modern Contisbury, Devon) with a force of more than a thousand to attack the West Saxons in the rear. But Odda, Ealdorman of Devon, had sallied forth from the fortress in a surprise dawn attack, massacring Ubba’s Vikings in their camp and capturing their Raven Banner. Trapped, starved, and with no hope of relief, Guthrum was forced to admit defeat.

An Unusual Peace

Just as King Alfred’s asymmetric campaign against the Great Heathen Army was unusual, so too was the peace treaty that King Alfred and Guthrum struck in May 878 CE (known as the Treaty of Wedmore). The truce contained the usual exchanges of hostages, and the agreement that Guthrum would withdraw from West Saxon territory – but it also stipulated that the pagan commander Guthrum would be baptized as a Christian, by Alfred himself. We can only guess at the motivations of the two men in undertaking this public ritual – Guthrum may well have been getting tired of the fruitless campaigns against the indefatigable West Saxons, and King Alfred spied an opportunity to open the door to bringing at least part of the Viking hordes under his influence.

The baptism of Guthrum as Æthelstan, attended by King Alfred (in blue) – from a Late Medieval stained glass window, Blakeney, Norfolk (via Alamy)

Regardless, the sources tell us that King Alfred and Guthrum performed this solemn ritual, and Guthrum took the Anglo-Saxon baptismal name Æthelstan, meaning ‘noble stone’. Shortly after the Great Heathen Army withdrew to East Anglia. The defeat at Edington marks the end of the military campaigns of the Great Heathen Army. But their story is not yet done. Guthrum did not merely remain as a baptized Viking commander, and his people did not remain under arms. He established himself as King of East Anglia, and the warriors of the Great Heathen Army were given land to farm in the fertile lowlands.

The Start of the Danelaw

In 886 (eight years after the Battle of Edington), Alfred and Guthrum finalized up a more permanent treaty, formalizing the relationship between the two powerful men and establishing a peaceful co-existence between Viking and English. The document, known as the Treaty of King Alfred and Guthrum, survives in several different written sources, and though they differ in details, they agree in their general principles. They refer to both Alfred and Guthrum as King: of the West Saxons and of East Anglia respectively. Guthrum was to acknowledge the overlordship of King Alfred and serve him as a bannerman, and in return, Alfred would acknowledge he and his pagan vassals as the legitimate kings of East Anglia.

The territorial division of England set out by the Treaty of Alfred and Guthrum c. 886 CE (via Before1066)

The document sets out the weregild (death-taxes) associated with the Christians and Norse who now lived side-by-side in much of England: tellingly, it placed an equal value on their lives, bringing the Viking settlers formally into the legal structures of Anglo-Saxon England. The Treaty of King Alfred and Guthrum is seen as the formal beginning of the Danelaw: the legal and political partition of England between Anglo-Saxon and Viking kingdoms, which would last for three-quarters of a century.

The End of the Viking Wars

One of the main consequences of the Great Heathen Army was the rise of Wessex. With the other Anglo-Saxon Kingdoms devastated and their kings deposed, the path to overlordship of the island was cleared for the West Saxons. In a series of wars against the fragmented Viking kingdoms, King Alfred’s successors would forge the whole of England into a unified Kingdom. The final Viking territory was Northumbria, which remained under Viking domination until King Eric Bloodaxe was deposed in 954 CE, after which time it was absorbed by the growing united Kingdom of England. The links between the Anglo-Saxon aristocracy and the Scandinavian incomers would result in wars of position for the English throne in the early 11th century – finally resulting in the brief formation of a North Sea Kingdom uniting Norway, Sweden, Denmark and England under King Cnut.

The distribution of Scandinavian-derived place names in modern England, and Watling Street, the border between Alfred and Guthrum’s realms. (from A. H. Smith (1956) English Place-Name Elements).

But beneath the surface of politics, there were deeper changes brought about by the Great Heathen Army. The North and East of England took a long time to recover from the widespread depopulation and political fragmentation caused by the invasion, though towns like York became very rich North-facing trading centers. The gradual formation of a hybrid Anglo-Scandinavian culture, language and political society further accentuated the difference between North and South in England – differences which remain to this very day.


About Charles J Lockett

Ever since Charles was a lad, he’s been a history obsessive – summer holidays were always spent dragging his family around Welsh castles! He pursued that passion through University, studying Early-Modern Europe and the French Revolutions, receiving his MA in Politics from the University of Sheffield. Nowadays, he is a writer specialising in history and politics, based in Yorkshire, UK. In his spare time, he is a Dungeon Master, aspiring fantasy novelist and cat dad.