Several Reasons Why Vikings Had Huge Success in War
The Vikings were successful in war because their ships let them choose where and when to fight. Shallow-draught longships could land on a beach or row far up a river, so a crew could strike an undefended monastery or town and be gone before an army gathered. Rich, unguarded targets, winter camps that kept armies in the field, and rulers who paid them to leave did the rest. They lost often too, and no single reason explains the roughly 270 years of raiding between Lindisfarne in 793 and 1066.
A Couple of Reasons Why the Vikings Had Such Huge Success in War
The reasons work on two levels. On the level of the single warrior there were his training, his weapons and his willingness to fight. On the level of the army there were the ships, the choice of targets, the camps, and leaders who knew when to fight and when to take payment instead.
The ships come first. The warships sold today under the name Drakkar ships carried the raiders, although drakkar itself is a modern word: it is first recorded in French in 1840, borrowed from Swedish, and the Old Norse word behind it, dreki, 'dragon', was a name for a great warship. With ships the raiders could appear without warning, and surprise won many raids. It did not win all of them.
Viking armies were beaten too, and archaeology has found some of the dead. On Ridgeway Hill near Weymouth in Dorset, a pit dug in the late tenth or early eleventh century held about fifty young men, all of them beheaded, and isotope analysis points to Scandinavian origins for many of them. At Repton in Derbyshire, where the Anglo-Saxon Chronicle says the Great Army wintered in 873 to 874, excavators found the remains of at least 264 people buried together in one building, and radiocarbon dates published in 2018 fit the army's stay.
Raids from the sea
Raiders came from the sea, struck the coast and were gone before a defence could gather. The best-known early raid hit the monastery of Lindisfarne, the Holy Island off the coast of Northumbria, in 793. It was not the first. The Anglo-Saxon Chronicle records three ships of Northmen in the days of King Beorhtric of Wessex, whose crew killed the king's reeve when he rode out to meet them, and calls them the first ships of Danish men to seek the land of the English. Scandinavian warriors were crossing the Baltic even earlier: around 750, two ships at Salme on the Estonian island of Saaremaa were used to bury 41 men killed in fighting, and isotope analysis points to central Sweden as their home. (Lindisfarne 793 is where our interactive Viking World Map begins, with raids, routes and settlements plotted with their sources.)
The chronicle's entry for 793 tells of whirlwinds, lightning and fiery dragons in the sky over Northumbria, then of famine, and then of heathen men destroying God's church on Lindisfarne with plunder and slaughter. Alcuin of York, a Northumbrian scholar at the court of Charlemagne, wrote to the Northumbrian king that nothing so terrible had been seen in Britain before, and urged the Northumbrians to ask whether their own sins had brought it on them. Ireland was struck soon after: the Annals of Ulster record the burning of Rechru, an island off the Irish coast, by heathens in 795.
Coastal monasteries and trading places lived under that threat for generations. The raiding bands were small compared with the people of a kingdom, but they did not need to beat a kingdom. They needed to beat the few men who could be gathered on the day, or to be gone before anyone came.
Rivers, camps and conquest
The same ships could row far inland. In March 845, the Annals of Saint-Bertin say, 120 ships of Northmen went up the Seine, laying waste on both banks, and reached Paris with no one standing in their way. King Charles the Bald, seeing that his men could not win, paid them 7,000 pounds to go back. On the Loire in 843 a fleet sacked Nantes and killed its bishop, then wintered on an island in houses brought over from the mainland, as if to stay for good. In England the Great Army used the rivers the same way: the Anglo-Saxon Chronicle has it wintering at York on the Ouse, at Reading and London on the Thames, and at Torksey and Repton on the Trent. In Ireland the Annals of Ulster record a naval camp at Dublin in 841, from which the surrounding peoples and churches were plundered. Further east, Scandinavians travelled the rivers of what is now Russia and Ukraine, hauling their ships overland past the rapids of the Dnieper.
Some of these raiders stayed. Rollo, a leader of the Northmen on the Seine, received land around Rouen from Charles the Simple, king of West Francia. Dudo of Saint-Quentin, writing about a century later, describes the agreement, and historians traditionally date it to 911; the earliest document to mention the grant is a charter of Charles from 918, which speaks of land given to the Northmen of the Seine, Rollo and his companions. In Haralds saga hárfagra Snorri Sturluson identifies Rollo with the Norwegian Göngu-Hrólfr, 'Walking Hrólfr', who won a great earldom in France that came to be called Normandy, while Dudo makes him a Dane. Later tradition calls Rollo the first duke of Normandy, though the title duke only became usual for his descendants around the year 1000. Nor was he the first Viking to rule a land: the Anglo-Saxon Chronicle says that in 876 Healfdene shared out the land of the Northumbrians, and that in 880 the army Alfred had beaten at Edington settled in East Anglia and divided the land.
The chronicle calls the force that landed in East Anglia in 865 a great heathen army, and mostly calls its men Danes. Unlike the first raiders it stayed: it took York in 867, killed King Edmund of East Anglia, drove King Burhred out of Mercia in 874 and set up kings of its own choosing. It was not unstoppable. Alfred of Wessex beat it at Edington in 878, and in the tenth century Alfred's successors won back the Danelaw. At Brunanburh in 937 King Æthelstan defeated an alliance of the Dublin Norse and the Scots, and the last Norse king of York, Eiríkr, was driven out in 954. In Ireland and northern Britain the descendants of Ímar (Ívarr), a Norse dynasty, ruled Dublin and at times York; the Irish called the Norse Gaill, 'foreigners', as distinct from the Gaels. (You can sail the Great Heathen Army's whole campaign, 865 to 878, landing to Wessex, as a guided journey on the Viking World Map.)
How big were these armies? The chroniclers' numbers deserve caution. The Annals of Saint-Bertin give 120 ships at Paris in 845 and, the same year, 600 ships for the Danish king Horik on the Elbe, a fleet the Saxons defeated. Abbo of Saint-Germain, who lived through the siege of Paris in 885 to 886, says in his verse account of the siege that 700 ships came up the Seine, besides smaller boats beyond counting. The Anglo-Saxon Chronicle has 350 ships come into the mouth of the Thames in 851. Historians read such figures as the impressions of frightened witnesses rather than counts, and the size of the Great Army of 865 is still debated, with estimates ranging from a few hundred men to a few thousand.
Ships
And now, about those warships. They were clinker-built, with overlapping planks of split oak or, in western Norway, pine, riveted together with iron, and they were driven by both oars and a single square sail. Oars let a crew move without wind, hold position in a fjord or come in against a shore; the sail carried them across open sea. One of the best preserved Viking ships is the Gokstad ship, dug out of a Norwegian burial mound in 1880 and kept in Oslo by the Museum of the Viking Age, which is closed for rebuilding until 2027.
The Gokstad ship was built around 890 and buried around 900. The Oslo museum gives it as 23.22 metres long and 5.18 metres wide, with 16 oar holes a side and room for a crew of up to 67, with two men to each oar. That is broad for a warship. The Viking Ship Museum in Roskilde defines a longship as a ship driven by both oars and sail and at least five times as long as it is wide, and the true longships come from later finds. The great longship Skuldelev 2, built near Dublin around 1042, was about 30 metres long, with 60 oars and a crew of 65 to 70.
What made these ships so useful in war was how little water they drew. The Roskilde museum gives the small longship Skuldelev 5, 17.3 metres long, a draught of only 0.6 metres, and the great Skuldelev 2 about 1 metre. A crew could run such a ship onto a beach or row it far up a river. Sailing full-size reconstructions, the museum gives Skuldelev 5 an average speed of 6 to 7 knots and a top speed of about 15, and Skuldelev 2 an average of 6 to 8 knots and an estimated top speed of 17.
The ships changed over time. Merchant ships, the knörr, were broader and deeper and relied on the sail, while warships stayed long and narrow. As the Roskilde museum notes, the ships of the late Viking Age looked quite different from the early ships buried at Tune, Gokstad and Oseberg.
The longships were not built to ram or sink other ships. When fleets met, as at the battle of Svolder in the year 1000, which Snorri Sturluson describes in Óláfs saga Tryggvasonar, the defenders lashed their ships together into one fighting platform and the attackers boarded them one by one, so a sea battle was fought much like a land battle. The English learned to fight at sea as well. The Anglo-Saxon Chronicle says that in the 890s King Alfred had long ships built against the Danish raiders, nearly twice as long as theirs, some with sixty oars or more, swifter, steadier and higher. Their first fight, off the south coast, was a confused struggle on an ebbing tide, with ships of both sides stranded on the mud.
The Gokstad ship is the main motif of Norway's 100-krone note, in circulation since 2017, a sign of how much the Viking ships still mean in Norway today.
Land battles
Ships brought the warriors; fighting on land decided the rest. The most famous Viking fighters are the berserkers, and almost everything said about them comes from a few texts. In Haraldskvæði, a poem about King Harald Fairhair's sea battle at Hafrsfjord, the berserkers bellow and the úlfheðnar, the 'wolf-coats', howl. Snorri Sturluson, writing around 1230, describes their frenzy in Ynglinga saga (ch. 6) as one of Odin's arts: Odin's men went without mail, were as mad as dogs or wolves, bit their shields and were as strong as bears or bulls, and neither fire nor iron harmed them. Vatnsdæla saga says the wolf-coats wore wolf-skin coats instead of mail and guarded the prow of the king's ship.
In the Icelandic sagas berserkers are more often trouble than heroes: duel-seeking bullies whom the hero kills. The Icelandic law code Grágás punished going berserk with lesser outlawry, and no source describes berserkers as a regular unit in Viking armies. Explanations for the frenzy are modern. The idea that berserkers ate fly agaric mushrooms was put forward by the Swedish clergyman Samuel Ödmann in 1784, more than five centuries after the sagas were written; no Old Norse text mentions a mushroom or a potion, and theories about adrenaline or other drugs are guesses too. Nor did the monks who suffered the raids write about berserkers. The English and Irish chroniclers call the raiders heathens, Northmen and Danes.
And what did those battle cries actually sound like? Two that survive with a named source are “Óðinn á yðr alla!” (“Odin owns you all!”), called out by Eiríkr the Victorious as he dedicated the enemy army to Odin before battle, and the Stiklestad cry “Fram, fram!” (“Forward, forward!”), shouted by King Óláfr's army in 1030. Both are in the original Old Norse, with runes and sources, in our collection of real Viking quotes.
Shield walls, ambush and the wedge
Most land battles were fought on foot and in close order. Warriors stood shoulder to shoulder with their shields overlapping in a shield wall, and their English enemies fought the same way: the poem on the battle of Brunanburh in the Anglo-Saxon Chronicle says that Æthelstan and his brother Edmund clove the enemy's 'board-wall', bordweal. Arrows and thrown spears came first, then the lines closed. Saxo Grammaticus, writing in Denmark around 1200, says Odin himself taught kings a wedge-shaped formation, which Old Norse writers called svínfylking, the 'swine array'. Saxo's kings are legendary, and how often real Viking-Age armies fought in a wedge is unknown.
Surprise mattered more than formation. In 865, the Anglo-Saxon Chronicle says, the army on Thanet made peace with the men of Kent for a promise of money, then stole away by night and ravaged all of eastern Kent. Once ashore, raiders took horses and moved fast: the Great Army wintered in East Anglia, where it was soon horsed. Mobility on water and on land let a Viking army choose where to fight, and it could build a fortified camp where it stopped, as the army did by the river Lea above London in the 890s.
Why monasteries came first
Monasteries were the first targets for plain reasons. They held silver, gold and church treasures, many of them stood on islands or coasts, and nobody defended them. Raiders who did not share the Christian respect for holy places had no reason to spare them. Irish kings sometimes plundered churches as well, as the Irish annals record, but the Vikings came from the sea and without warning. Silver taken in raids paid for more ships and more followers, which is how small raiding bands could grow into the great armies of the ninth century.
Tribute: paid to go away
Often the Vikings did not need to fight at all, because rulers paid them to leave, a payment later known as Danegeld. The 7,000 pounds Charles the Bald paid at Paris in 845 was one of many such payments in Francia. In England the Anglo-Saxon Chronicle presents 991, the year of the defeat at Maldon, as the first time tribute was paid to the Danes: 10,000 pounds. Then the sums grew, to 16,000 pounds in 994, 24,000 in 1002, 30,000 in 1007 and 48,000 in 1012. In 1018 Cnut, by then king of England, raised 72,000 pounds from the whole country and another 10,500 from London; then part of the army went home to Denmark, and forty ships stayed with Cnut. These figures come from the chronicle and may be rounded, but they show how much silver war could bring to Scandinavia.
Weapons
How many of you picture axes as the Viking weapon? The axe was both a tool and a weapon. Every farm needed axes for felling trees and splitting wood, an axe took less iron than a sword, and a simple iron-and-wood axe could go to war as easily as to the woodpile. Axes with broad, thin blades made for fighting became especially common in the late Viking Age. You can see the same shapes echoed in our own hand-forged Viking axes today.
Spears were probably the commonest weapon of all. A spearhead needed far less iron than a sword, and a spear kept the enemy at a distance. Some were made for thrusting and lighter ones for throwing; Snorri's account of Svolder has spears and arrows flying so thickly that men could hardly get their shields in front of them. Bows and arrows were used both at sea and on land.
Swords were the costliest weapons and a mark of rank. A good blade took a great deal of skilled work, and many of the best were imported from the Frankish lands. The most famous carry the inlaid name +VLFBERH+T; more than a hundred Ulfberht swords are known, and not all of them are of the same quality. Swords were handed down in families and, in the sagas, given names. The sagas also tell of duels fought to settle quarrels, and Grettis saga says Earl Eiríkr Hákonarson abolished duelling in Norway.
On the defensive side the round wooden shield was the warrior's main protection. Ingvald Undset's 1898 guide to the Gokstad ship describes its shields as boards held together by the hand grip, with an iron boss in the middle to protect the hand and traces of a binding, probably of leather, round the edge. Helmets and mail were rare and expensive. Only two nearly complete Viking-Age helmets are known: the Gjermundbu helmet, found in nine pieces in a rich grave in Ringerike, Norway, in 1943, together with the remains of a mail shirt, and the Yarm helmet from northern England, which was only recently shown to be Viking-Age. Neither has horns. Horned Viking helmets come from nineteenth-century art and opera costume, not from the Viking Age.
In conclusion
Many Viking warriors were farmers who owned a spear, an axe and a shield, while a sword, a helmet or a mail shirt marked a richer man or a king's follower. What gave them the edge was not better armour but the initiative. Ships let them choose the target and the moment, rivers took them deep into kingdoms, winter camps kept armies in the field year after year, and rulers who could not beat them paid them instead. Where kingdoms organised against them, with fortified towns, fleets and armies that could be raised quickly, the Vikings were beaten as often as anyone else.
Word of thought by the writer
So, there you have it. The Viking Age of raiding ran from Lindisfarne in 793 to 1066, when King Harald Hardrada of Norway fell at Stamford Bridge: about 270 years, not four centuries. Over that time the small crews that struck monasteries grew into the Great Army that conquered kingdoms, and raiders became settlers, traders and rulers in England, Ireland, Normandy and the lands to the east. Many of them mixed with the people they had raided, and their descendants came to speak English, Irish and French.
The Vikings are still remembered for their wars, and recent television series have made them more famous than ever. The sources give a more human picture: skilled sailors and opportunists who won when they could choose the fight, and lost when they could not.
Keep exploring: see our Viking history timeline for the full chronology, plus famous Viking battles and the weapons Vikings carried.
Why Were the Vikings So Successful in War? FAQ
Why were the Vikings so successful in war?
No single reason: it was a combination. Shallow-draught ships let them land on beaches and row far up rivers, so they could strike undefended monasteries and towns by surprise and leave before an army gathered. Winter camps kept their armies in the field, and many rulers paid them tribute rather than fight. They also lost many battles.
What weapons did the Vikings use?
The spear and the axe were the common weapons, because they needed less iron than a sword. Swords were costly and marked rank; some of the best blades carry the name +VLFBERH+T. For defence warriors carried round wooden shields with an iron boss. Helmets and mail shirts were rare, and no Viking helmet found so far has horns.
What was the Great Heathen Army?
The army that the Anglo-Saxon Chronicle calls a great heathen army, which landed in East Anglia in 865; the chronicle mostly calls its men Danes. Unlike the earlier hit-and-run raiders it stayed for years, wintering in one kingdom after another. It conquered Northumbria, East Anglia and much of Mercia before Alfred of Wessex defeated it at Edington in 878.
How fast were Viking longships?
It depended on the ship. Sailing full-size reconstructions, the Viking Ship Museum in Roskilde gives the small longship Skuldelev 5 an average of 6 to 7 knots and a top speed of about 15, and the great longship Skuldelev 2 an average of 6 to 8 knots and an estimated top speed of 17. Skuldelev 5 drew only 0.6 metres of water and Skuldelev 2 about 1 metre, shallow enough to land on a beach or row far up a river.
Did berserkers eat mushrooms before battle?
No Old Norse text says so. The sources describe a frenzy, berserksgangr, that came over a man, and none mentions a mushroom, a potion or any other substance. The fly agaric idea was put forward by the Swedish clergyman Samuel Ödmann in 1784, more than five centuries after the sagas were written, and it remains a modern guess.
What did the Vikings shout in battle?
Very few battle cries survive with a named source. Two that do are “Óðinn á yðr alla!” (“Odin owns you all!”), called out by Eiríkr the Victorious, and the Stiklestad cry “Fram, fram!” (“Forward, forward!”).
Resources
The Annals of Ulster (CELT, University College Cork): entries for 795 and 841
Annales Bertiniani, ed. G. Waitz, 1883: entries for 843 and 845 (Latin text)
Snorri Sturluson, Heimskringla: Ynglinga saga, ch. 6 (Old Norse text)
Snorri Sturluson, Heimskringla: Haralds saga hárfagra (Old Norse text)
Snorri Sturluson, Heimskringla: Óláfs saga Tryggvasonar, the battle of Svolder (Old Norse text)
Saxo Grammaticus, The Danish History, Books I to IX, trans. O. Elton (Project Gutenberg)
The Viking Ship Museum, Roskilde: The five Viking ships (Skuldelev 1, 2, 3, 5 and 6)
The Viking Ship Museum, Roskilde: Sea Stallion from Glendalough, the reconstruction of Skuldelev 2
The Viking Ship Museum, Roskilde: Findings of longships from the Viking Age
The Viking Ship Museum, Roskilde: Longship research
Museum of the Viking Age, Oslo: The Gokstad Ship
Ingvald Undset, A Short Guide for the Use of Visitors to the Viking-Ship from Gokstad, 1898