Great Heathen Army The Great Heathen Army ( OE : " mycel heathen here " ) , also known as the Great Danish Army or The Great Viking Army , was a group of hitherto uncoordinated bands of vikings that originated from Denmark , Norway and southern Sweden who came together under a unified command to invade England in 865 AD . Since the late 8th century the Vikings had settled for mainly " hit - and - run " raids on centres of wealth such as monasteries . However , the intent of the Great Army was different , it was much larger than the usual raiding party and its purpose was to conquer . The name is derived from the Anglo - Saxon Chronicle of 865 . Legend has it that the force was led by the sons of Ragnar Lodbrok . The campaign of invasion and conquest against the four remaining Anglo - Saxon kingdoms lasted fourteen years . Unlike many of the Scandinavian raiding armies of the period , surviving sources give no firm indication of its numbers , but it was clearly among the largest forces of its kind . The invaders initially landed in East Anglia where the king provided them with horses for their campaign in return for peace . They spent the winter of 865 – 66 at Thetford before marching north to capture York in November 866 . During 868 they marched deep into Mercia and wintered in Nottingham , where they were besieged by a joint force from the kingdoms of Mercia and Wessex . With no progress being made , the Mercians agreed to terms with the Viking army , which moved back to York for the winter of 869 – 70 . In 870 the Great Army returned to East Anglia , conquering it and killing its king . They moved to winter quarters in Thetford . In 871 the Vikings moved on to Wessex , where Alfred the Great was content to pay them to leave . The army then marched to London to overwinter in 872 before moving back to Northumbria in 873 . They again returned to Mercia , conquering it in 874 . By this time only the kingdom of Wessex had not been conquered by the invading Vikings . It was towards the end of 875 , when the army started their second invasion of Wessex . After a few setbacks , Alfred the Great defeated them at the Battle of Edington , and a treaty was agreed upon , whereby the Vikings were able to remain in control of much of northern and eastern England . Background . Viking raids began in England in the late 8th century , primarily on monasteries . The first monastery to be raided was in 793 at Lindisfarne , off the northeast coast ; the Anglo - Saxon Chronicle described the Vikings as " heathen men " . Monasteries and minster churches were popular targets as they were wealthy and had valuable objects that were portable . The Anglo - Saxon Chronicle for the year 840 says that Æthelwulf of Wessex was defeated at Carhampton , Somerset , after 35 Viking ships had landed in the area . The Annals of St . Bertin also reported the incident , stating : " The Northmen launched a major attack on the island of Britain . After a battle lasting three days , the Northmen emerged the winners – plundering , looting , slaughtering everywhere . They wielded power over the land at will . " Despite this setback Æthelwulf did have some success against the Vikings . The Anglo - Saxon Chronicle has repeated references during his reign of victories won by ealdormen with the men of their shires . However , the raiding of England continued on and off until the 860 ' s , when instead of raiding the Viking changed their tactics and sent a great army to invade England . This army was described by the Anglo - Saxon Chronicle as a " Great Heathen Army " ( OE : " mycel hæþen here " or " mycel heathen here " ) . The size of the army . Historians provide varying estimates for the size of the Great Heathen Army . According to the ' minimalist ' scholars , such as Pete Sawyer , the army may have been smaller than traditionally thought . Sawyer notes that the Anglo - Saxon Chronicle of 865 referred to the Viking force as a Heathen Army , or in Old English " " hæþen here " " . The law code of King Ine of Wessex , issued in about 694 , provides a definition of " " here " " as " an invading army or raiding party containing more than thirty five men " , thus differentiating between the term for the invading Viking army and the Anglo - Saxon army that was referred to as the " fyrd " . The scribes who wrote the Anglo - Saxon chronicle used the term " " here " " to describe the viking forces . The historian Richard Abels suggested that this was to differentiate between the viking war bands and those of military forces organised by the state or the crown . However by the late 10th and early 11th century " here " was used more generally as the term for army , whether it was viking or not . Sawyer produced a table of viking ship numbers , as documented in the Anglo - Saxon Chronicle , and assumes that each Viking ship could carry no more than thirty two men , leading to his conclusion that the army would have consisted of no more than 1000 men . Other scholars give higher estimates . For example , Laurent Mazet - Harhoff observes that many thousands of men were involved in the invasions of the Seine area . However he does say that the military bases that would accommodate these large armies have yet to be rediscovered . Guy Halshall reported that in the 1990s several historians suggested that the Great Heathen Army would have numbered in the low thousands ; however Halshall advises that there " clearly is still much room for debate " . The army probably developed from the campaigns in France . In Francia there was a conflict between the Emperor and his sons , and one of the sons had welcomed the support from a Viking fleet . By the time the war had ended , the Vikings had discovered that monasteries and towns situated on navigable rivers were vulnerable to attack . In 845 a raid on Paris was prevented by the large payment of silver to the Vikings . The opportunity for rich pickings drew other Vikings to the area , and by the end of the decade all the main rivers of West Francia were being patrolled by Viking fleets . In 862 the West Frankish king responded to the Vikings , fortifying his towns and defending his rivers , thus making it difficult for the Vikings to raid inland . The lower reaches of the rivers and the coastal regions were left largely undefended . Religious communities in these areas , however , chose to move inland away from the reaches of the Viking fleets . With the changes in Francia making raiding more difficult , the Vikings turned their attention to England . Invasion of England . The term ' viking ' simply meant pirate , and the viking " heres " may well have included nationalities other than Scandinavian . The viking leaders would often join together for mutual benefit and then dissolve once profit had been achieved . Several of the viking leaders who had been active in Francia and Frisia joined forces to conquer the four kingdoms constituting Anglo - Saxon England . The composite force probably contained elements from Denmark , Norway , Sweden and Ireland as well as those who had been fighting on the continent . The Anglo - Saxon historian Æthelweard was very specific in his chronicle and said that " " the fleets of the viking tyrant Ivar the Boneless landed in England from the north " " . The bulk of the army consisted of Danish vikings , who prior to the invasion would have been raiding Francia and Frisia . Some of the grave goods unearthed at Repton , where the Great Heathen Army spent the winter in 874 , were of Norwegian origin , indicating that part of the army was likely to have contained elements of Norwegian Vikings , who would have been operating in Britain , raiding and conquering lands around the Irish Sea . The Great Heathen Army would also have consisted of various independent bands , or liðs , coming together under a joint leadership . The Vikings had been defeated by the West Saxon King Æthelwulf in 851 , so rather than land in Wessex they decided to go further north to East Anglia . Legend has it that the united army was led by the three sons of Ragnar Lodbrok : Halfdan Ragnarsson , Ivar the Boneless , and Ubbe Ragnarsson . Norse sagas consider the invasion by the three brothers as a response to the death of their father at the hands of Ælla of Northumbria in 865 , but the historicity of this claim is uncertain . Start of the invasion , 865 . In late 865 the Vikings landed in East Anglia and used it as a starting point for an invasion . The East Anglians made peace with the invader by providing them with horses . The Vikings stayed in East Anglia for the winter before setting out for Northumbria towards the end of 866 , establishing themselves at York . In 867 the Northumbrians paid them off , and the Viking Army established a puppet leader in Northumbria before setting off for the Kingdom of Mercia , where in 867 they captured Nottingham . The king of Mercia requested help from the Wessex king to help fight the Vikings . A combined army from Wessex and Mercia besieged the city of Nottingham with no clear result , so the Mercians settled on paying the Vikings off . The Vikings returned to Northumbria in autumn 868 and overwintered in York , staying there for most of 869 . They returned to East Anglia and spent the winter of 869 – 70 at Thetford . There was no peace agreement between the East Anglians and the Vikings this time . When the local king Edmund fought against the invaders , he was captured and killed . In 871 , the Great Summer Army arrived from Scandinavia , led by Bagsecg . The reinforced Viking army turned its attention to Wessex , but the West Saxons , led by King Æthelred ' s brother Alfred , defeated them on 8 January 871 at the Battle of Ashdown , slaying Bagsecq in the process . Three months later Æthelred died and was succeeded by Alfred ( later known as Alfred the Great ) , who was at first content to buy the Vikings off to gain time . During 871 – 72 , the Great Heathen Army wintered in London before returning to Northumbria . It seems that there had been a rebellion against the puppet ruler in Northumbria , so they returned to restore power . They then established their winter quarters for 872 - 73 at Torksey in Lindsey ( now part of Lincolnshire ) . The Mercians again paid them off in return for peace , and at the end of 873 the Vikings took up winter quarters at Repton in Derbyshire . In 874 , following their winter stay in Repton , the Great Heathen Army drove the Mercian king into exile and finally conquered Mercia ; the exiled Mercian king was replaced by Ceowulf . According to Alfred the Great ' s biographer , Asser , the Vikings then split into two bands . Halfdan led one band north to Northumbria , where he overwintered by the river Tyne ( 874 – 75 ) . In 875 he ravaged further north to Scotland , where he fought the Picts and the Britons of Strathclyde . Returning south of the border in 876 , he shared out Northumbrian land amongst his men , who ' ploughed the land and supported themselves ' , part of what became known as the Danelaw . King Alfred ' s victory . According to Asser , the second band was led by Guthrum , Oscetel , and Anwend . This group also left Repton in 874 and established a base at Cambridge for the winter of 874 – 75 . In late 875 they moved onto Wareham , where they raided the surrounding area and occupied a fortified position . Asser reports that Alfred made a treaty with the Vikings to get them to leave Wessex . The Vikings left Wareham , but it was not long before they were raiding other parts of Wessex , and initially they were successful . Alfred fought back , however , and eventually won victory over them at the Battle of Edington in 878 . This was followed closely by what was described by Asser as the Treaty of Wedmore , under which England was divided between the Anglo - Saxons of Wessex and the Vikings . Guthrum also agreed to be baptised . Aftermath . In late 878 Guthrum ' s band withdrew to Cirencester , in the kingdom of Mercia . Then , probably in late 879 , it moved to East Anglia , where Guthrum , who was also known by his baptismal name of Aethelstan , reigned as king until his death in 890 . The part of the army that did not go with Guthrum mostly went onto more settled lives in Northumbria and York . Some may have settled in Mercia . Evidence for this is the presence of two Viking cemeteries in modern - day Derbyshire that are believed to be connected to the " Great Army " , at Repton and at Heath Wood . Excavations at the Anglo - Saxon monastery of Repton in the heart of Mercia between 1974 – 88 found a D - shaped earthwork on the river bank , incorporated into the stone church . Burials of Viking type were made at the east end of the church , and an existing building was cut down and converted into the chamber of a burial mound that revealed the disarticulated remains of at least 249 people , with their long bones pointing towards the centre of the burial . A large stone coffin was found in the middle of the mass grave ; however , the remains of this individual did not survive . A study of the skeletal remains revealed that at least 80 % of the individuals were male , and were between the ages of 15 and 45 . Further investigation of the male skeletal remains revealed that they were dissimilar to the local population of Repton , and most likely of Scandinavian descent . In contrast , analysis of the female remains revealed that they were similar to the local population , suggesting an Anglo - Saxon lineage . It is possible that the people in the grave may have suffered some sort of epidemic when the army overwintered in Repton during 873 – 74 , leading to the mass burial . The nearby cemetery at Heath Wood contains about sixty cremations ( rather than burials ) . Finds of cremation sites in the British Isles are very rare , and this one probably was the war cemetery of the Great Heathen Army . In 878 , a third Viking army gathered on the Thames . It seems they were partly discouraged by the defeat of Guthrum but also Alfred ' s success against the Vikings coincided with a period of renewed weakness in Frankia . The Frankish emperor , Charles the Bald , died in 877 and his son shortly after , precipitating a period of political instability of which the Vikings were quick to take advantage . The assembled Viking army on the Thames departed in 879 to begin new campaigns on the continent . The rampaging Viking army on the continent encouraged Alfred to protect his Kingdom of Wessex . He built a navy , reorganised the army , and set up a system of fortified towns known as burh s . He mainly used old Roman cities for his burhs , as he was able to rebuild and reinforce their existing fortifications . Historically , every freeman in the land could be called out to protect the realm in times of trouble . Unfortunately , the speed of Viking hit - and - run raids had been too quick for the local militias to act , so part of Alfred ' s reforms were to create a standing army that could react rapidly to attacks . The Anglo - Saxon rural population lived within a 24 km ( 15 - mile ) radius of each burh , so they were able to seek refuge when necessary . To maintain the burhs , as well as the standing army , Alfred set up a system of taxation and conscription that is recorded in a document , now known as the Burghal Hidage . By 896 , the remains of the Danish army that had not gone to East Anglia or Northumbria found it difficult to make any progress in Alfred ' s fortified kingdom , so according to the " Anglo - Saxon Chronicle " those that were penniless found themselves ships and went south across the sea to the Seine . As for Anglo - Saxon England , it had been torn apart by the invading Great Heathen Army , and the Vikings were now in control of northern and eastern England , while Alfred and his successors remained in control of Wessex .