May 878
The Battle of Ethandun took place between 6 and 12 May 878. It pitted the forces of Wessex, led by Alfred the Great, against the Danish invaders of Guthrum the Elder.
The battle lasted most of the day and ended in victory for Alfred, who fought behind a defensive rampart of shields reminiscent of the tactics of the Roman legions. The Danes fled to the Danelaw, and finally surrendered at Chippenham, after a siege of fourteen days. The Danish king was subsequently baptized, with Alfred as godfather.
Despite the signing of the Treaty of Wedmore, then the treaty between Alfred and Guthrum, the state of war continued between Danes and Anglo-Saxons.
The battle is usually located in Edington, Wiltshire, but not certain. Other locations have been proposed, including Edington in Somerset.
Possible battlefield locations in England
According to the Peterborough Chronicle, Viking attacks on England date back to 793, when a raid on Lindisfarne Abbey in Northumbria. The Vikings made occasional attacks on Wessex after Lindisfarne, but did not pose a real threat until after the Battle of Carhampton in 836. Throughout the ninth century the Danes resolutely invaded England, pressing the Anglo- Saxons who populated the area. The people of Wessex at first managed to reasonably contain the threat, even when the invaders allied themselves with the Cornish Britons, but things went downhill from 851. When the Great Heathen Army arrived in 865, they had been engaged for fourteen years in vast campaigns which had cost them considerable losses.
The Great Heathen Army was not very large, and does not really correspond to the modern idea of an army:Jones estimates that it consisted of between five hundred and a thousand men, led by the Ivar brothers, Ubbe and Halfdan Ragnarsson. The difference between this army and the other Vikings that had preceded it was its purpose. His arrival triggered “a new stage, that of conquest and settlement”. By 870 the Danes had conquered the kingdoms of Deira and East Anglia, and they attacked Wessex in 871. Of the nine battles mentioned by the Anglo-Saxon Chronicle for that year, only one was won by the Saxons. King Æthelred died shortly after Merton's defeat, and his brother Alfred succeeded him.
In 874, Mercia collapsed, and the cohesion of the Grand Army with it. Halfdan returned to Deira and faced the Celts there; his army settled there and it is not mentioned again after 876. Accompanied by two kings whose names are unknown, Guthrum set out for Cambridge and from 875 repeatedly raided Wessex, failing to capture Alfred who was wintering in Chippenham in the last of these offensives.
By 878 the Danes controlled the east and northeast of England; their defeat at Ashdown had slowed them down, but not stopped them. Alfred spent the winter before the Battle of Ethandun at Athelney, protected by the marshes of the Somerset Levels. In the spring of 878, he gathered his forces and marched to Ethandun, where he met the Danes, led by Guthrum the Elder.
Alfred's position before the battle
Guthrum applied the usual Danish strategy:occupy a fortified place and wait for a peace treaty, by which they would be given money in exchange for their immediate departure. In 875, Guthrum's army occupied Wareham. Alfred paid them to leave the country, but they captured Exeter, further afield in Alfred's kingdom, where in the fall of 877 a "firm peace" was made with Alfred, whereby the Danes pledged to leave his kingdom and never to return. They complied with the treaty, spending the rest of the year 877 (according to the Gregorian calendar) in Gloucester. Alfred spent Christmas in Chippenham, about fifty miles from Gloucester. The Danes attacked Chippenham "in the middle of winter, after Twelfth Night", probably during the night of January 6-7, 878. They captured the town and narrowly missed capturing Alfred himself. He had to flee "with meager forces" into the wild.
During this period, Alfred seems to have hunted down the Danes without much success throughout Wessex, while the invaders did as they pleased. The Anglo-Saxon Chronicle tries to make it appear that Alfred was keeping the initiative:it takes the form of a "dull chronicle, which laconically traces the movements of the victorious Danes while trying to give the impression that Alfred was slyly keeping the control", without really succeeding. Even if Alfred had been able to catch up with the Danes, it's unlikely he could have done anything. The mere fact that his army was unable to defend the stronghold of Chippenham, "at a time […] so unskilled in the art of poliorcetics", does not really suggest that it could have conquered the Danes in open battle. Between 875 and the end of 877 there was little Alfred could do to counter the Danes except repeatedly pay them off.
The battle
This became even more true after the attack on Twelfth Night. With his small troop, a meager fraction of the army he had at Chippenham, Alfred could not hope to recapture the town from the Danes, who had previously shown themselves capable of adapting themselves to the defense of fortified positions (e.g. at Reading in 871). He therefore withdrew to the south to regain his strength. The first mention of Alfred after the Chippenham disaster dates from around Easter, when he founded a fortress at Athelney. During the seventh week after Easter (between May 4 and 7), Alfred summoned his men to Ecgbryhtesstan (Egbert's Stone). Many men from the surrounding counties (Somerset, Wiltshire and Hampshire), among those who had not already fled, joined him. The next day Alfred's army took the road to Iley Oaks, then the road to Ethandun the following day. There, between May 6 and 12, the Saxons clashed with the Danes. According to the story in the Life of Alfred:
"Fighting fiercely, forming a dense wall of shields against the whole army of the heathen, and struggling long and brave...at last [Alfred] won the victory. He overthrew the pagans and made a great massacre of them, and striking down the fugitives, he pursued them to the fortress [Chippenham]. »
After the victory, when the Danes had taken refuge in Chippenham, the Saxons seized all the food that the Danes could have brought back during a sortie and waited. After two weeks, the starving Danes sued for peace, surrendering hostages to Alfred and vowing to leave his kingdom instantly, as usual, but further promising that Guthrum would accept baptism. This time, Alfred's victory was decisive, and unlike the treaties of Wareham and Exeter, it seemed more likely that the Danes would uphold their end of the treaty.
The main reason for Alfred's victory was probably the relative size of the two armies. The men of a single county could be a significant force, as those of Devon proved that same year by crushing Ubbe Ragnarsson's army at the Battle of Cynwit. Moreover, Guthrum had lost the support of the other Danish lords in 875, including Ivar and Ubbe. Danish forces which might have reinforced Guthrum had moved into East Anglia and Mercia before the attack on Wessex; others were lost in a storm off Swanage in 876-877, which sank 120 vessels.
Consequences
Partition of the British Isles between Viking (red), Saxon (light green) and Celtic (dark green) states after the peace following the Battle of Ethandun.
After Ethandun, the Danes were confined to the Danelaw, and Wessex, the last free Anglo-Saxon kingdom, remained untouched by Danish control. Had Alfred lost the battle, Guthrum would likely have conquered the entire kingdom. Guthrum's defeat deeply demoralized the Danes, and Wessex remained at peace for some years.
Another consequence of the battle, the baptism of Guthrum and his men at Aller, with Alfred as Guthrum's godfather, gave the King of Wessex a certain moral predominance over the warriors of the Danelaw.