By far the most devastating and widespread attacks in Europe during the ninth, tenth and eleventh centuries came from the Vikings of Scandinavia, with their military tactics evolving from raiding proficiency at set-piece battles and sieges. The Vikings were a Germanic people based in Norway, Sweden and Denmark, and their movements constitute the final wave of Indo-European migration and what historians refer to as the Viking Age (793-1066), using Anglo-centric dating bookends beginning with the Scandinavian raid on the monastery at Lindisfarne Monastery and ending with the battle of Stanford Bridge. Warriors, traders, superb shipbuilders and sailors, the Vikings pushed south from their homeland in their trademark longships and attacked the whole of Europe. Norwegian Vikings moved into Ireland and western England, while the Danes attacked eastern England, Frisia, and the Rhineland and navigated rivers to enter western Carolingian territories. Swedish Vikings controlled the Baltic Sea and pushed into Slavic areas in Eastern Europe. Moving into northwestern Russia, the Swedes sailed up and down that region’s rivers to Novgorod and Kiev and established fortified ports in these areas, ultimately influencing the development of early Russian civilization. Sailing down the Dnieper and Don Rivers to the Black Sea, they contacted the Byzantine Empire as both traders and raiders, and the Byzantine Emperor Basil II (r.976-1025) even hired Russo-Swedish Vikings, the Varangians, as his personal bodyguard. The Vikings also sailed west and settled in the Faroes Islands, Iceland, Greenland, and for a brief time, North America.     

The Viking Age of expansion and conquest had its beginnings in a culture permissive of ship-based raiding. The shore raid or strandhögg was an age-old Viking tradition, one where warriors would beach their longship, round up cattle and sheep, and then sail off. This form of medieval livestock rustling was even done in Scandinavia itself until it was outlawed by the rise of centralized monarchies in the ninth and tenth centuries, forcing the strandhögg into foreign waters. Raids against continental Europe and the British Isles brought more opportunities, with Vikings returning from their seasonal raids with young women and healthy youths for the thriving slave trade.           

There was no standardized Viking panoply, but typical Viking arms and armor consisted of sword or battle axe, spear, and a round, wooden shield thirty-to-forty inches in diameter with a central iron boss. Chiefs and veterans might also wear a leather helm or metal spangenhelm (a forerunner to the Norman conical helm) and ring-reinforced leather jerkin or mail hauberk. Vikings, like their Germanic forebearers, preferred the sword as their primary offensive arm, though the expense of this weapon often forced warriors to use axes and spears. The best swords were imported from Frankish lands (despite Carolingian capitularies threatening capital punishment if arms sellers were caught), though Scandinavian craftsmen usually fitted them with ornate hilts and grips of precious metal, bone, horn, and walrus ivory. Viking sword blades were usually pattern-welded and double-edged, averaging thirty-two inches in length, with a shallow fuller on each side to reduce the weight of these hefty blades.              

Scandinavian warriors also used battle axes and spears. The axe, which was nearly abandoned in warfare in the rest of Europe, found favor again in the hands of Vikings. Several types of axes were used during the Viking Age, tools for woodworking and shipbuilding, and dedicated weapons of war. Two of the most famous were the skeggøx or “bearded axe,” so-called because of its asymmetrical blade, and the Danish breidøx or “broad axe,” first seen at the end of the tenth century and made famous by the Anglo-Saxon Huscarls in defense of their king Harold Godwinson (r.1066) at the battle of Hastings in 1066.  The broad axe took its name from the blade’s distinctive crescent shape, generous size (usually twelve inches along its curved edge), and five-foot haft. This long-hafted axe also became the signature weapon of the Varangian Guard who protected Byzantine emperors for centuries.

Viking spears were of light and heavy varieties, the former was thrown as javelins and had narrow blades and slim shafts, while the latter were used for hand-to-hand combat and had broad, leaf-shaped blades and thicker, often iron-shod shafts. Both types of spear blade were socketed, and some had short, side lobes jutting out just above the socket. This last type is often referred to as the Viking “winged” spear. Finally, archery also held an important, if ancillary place in Viking warfare, as can be seen by the role missile fire played in both land and naval engagements. The bows themselves were of several types, including short and long varieties of self-bows (with staves made from a homogenous piece of wood). Composite bows were also used, due to trading and martial contacts with steppe peoples in Eastern Europe.

Early Viking raids were conducted normally in the summer with Scandinavian warriors sacking coastal villages and towns, destroying churches and monasteries, and easily defeating local, mostly infantry-based militias. In the first decades of the ninth century, Viking raiding involved small numbers of ships and were directed against Europe’s long coastline or the mouth or channels of major rivers. But the death of Charlemagne (r.768-814) in 814 and the chaos that followed under the weak rule of his son and successor Louis the Pious offered an attractive target for Viking marauders. As news spread of the wealth and vulnerability of the Frankish interior, Vikings appeared in greater numbers. By the 830s, larger Danish fleets were threatening England as well with seasonal raids. During the winter of 840-841, the Norwegian Vikings switched from seasonal raids to wintering in enemy territory, staying for the first time on a small island off the coast of Ireland. Eventually, they would create temporary raiding bases called longphorts. A longphort was a fortified Viking base with a harbor for longships in Ireland located at the mouth of a river where the ships could stop with both access to the open sea and move upriver for inland raiding. The camp was fortified with an outer wall in a muddy, boggy area, which was difficult to attack, and with a circular inner wall, which resembles the Ring Forts seen in Denmark. Some of these temporary longphorts evolved into permanent settlements, with the first and most famous mentioned in the Irish Annals was An Dubh Linn (Dublin), located in a boggy area known as "the Black Pool" on the south bank of the Liffey River. Other longphorts evolved into Waterford, Wexford, and Limerick. On the continent, when the Carolingian empire erupted into civil war at the death of Louis the Pious (r.814-840) in 843, Vikings set up similar bases at the mouth of Loire and Seine Rivers, then launched raids inland, sometimes on ships, sometimes on captured horses. 

The size of Viking armies also varied depending on the period. Early ninth century raids consisted of a few longships and a hundred warriors. As early as 845 Vikings were sailing inland from their longphorts at the mouth of the river Seine, investing, sieging, and plundering Paris on Easter Sunday of that year in a plundering expedition led by the legendary Norse saga figure Ragnar Lothbrok (sometimes Lodbrok). But by 865, Viking activity in Western Europe was concentrated in a “Great Heathen Army” made up of fleets of hundreds of ships carrying thousands of Viking warriors and led by several Scandinavian kings. Between 865 and 879 and again between 892 and 896, the “Great Heathen Army” plundered England with the Danes occupying an area known as Danelaw in northeastern England. Accepting Christianity, the Danes were eventually assimilated into the larger Anglo-Saxon kingdom, giving their greatest warriors, the Huscarls, to the English king as bodyguards. On the continent, another “Great Army” devastated Flanders, raided deep into the Rhine Valley, and even sieged Paris in the winter of 885-886 with as many as 40,000 men and seven hundred ships, though probably the numbers involved were much smaller.  

But as widespread as the Viking raiding and invasion was, the Vikings were, in fact, not particularly good at winning battles. Many of their victories came from attacking soft, undefended targets like churches and monasteries well stocked with ecclesiastical treasures and Mass wine, and unwalled towns and cities. When regional armies finally organized and offered determined resistance in the late ninth century, the fortunes of the Vikings changed. In England, the Anglo-Saxon king Alfred the Great (r.871-899) built walls around his towns, creating burhs, and founded the first English navy in 875 to intercept Danish fleets at sea. In France, cities walls were constructed (or if dilapidated by neglect, rewalled) and fortified bridges built across major rivers to close access to the interior. In order to block or discourage sea-borne penetrations of the Viking “Great Army” into the heart of Western Europe, the Frankish king Charles the Bald (r.843-877) built fortified bridges across strategic waterways. Charles placed these fortified spans at strategic locations such as Charenton-le-Pont on the Marne River, Auvers on the Oise River, and at Paris, Pistres, Pontoise, and Trilbardou on the Seine River and built and garrisoned the bridges with men too poor to go on campaign. The bridges consisted of a wooden superstructure and bridgehead forts of wood and stone. The effectiveness of these fortified bridges is mixed. With the exception of Paris, most of these bridges had limited success because of the difficulty of maintaining garrisons, as most were attacked and destroyed while under construction. Charles also ordered the restoration of walls at Orleans, Le Mans, and Tours and construction of a wall around the important monastery of St. Denis near Paris. After Charles’ death in 877, control of the fortified bridge near Paris fell to local commanders, who despite their best effort were unable to hold back a second Viking “Great Army” in 885 that sailed up the Seine and attacked Paris. Still, attacks on well-fortified targets were unusual in Viking warfare, and faced with a determined resistance, the Scandinavian marauders usually moved on. Moreover, when battle was offered by the defenders of a realm, the Vikings often preferred negotiations not to return for annual tribute or withdrawal to a set-piece engagement. To stop Viking attacks using the Seine River, the Frankish king Charles "the Simple," r.898-922) gave a land grant to a Norse adventurer named Rollo who converted to Christianity, married the king's daughter, and settled in the region of Normandy. His ancestors became known as the Normans who would shape the history of France, England, and Italy in the High Middle Ages.

The last great Viking invasion took place in 1066 when a massive Norwegian invasion fleet led by King Harald III Hardrada of Norway (r.1046-1066) set sail for England to challenge the new Anglo-Saxon king, Harold Godwinson, for the English crown. Though Hardrada would be ultimately defeated by Godwinson at the battle of Stamford Bridge using infantry tactics not dissimilar to those of the Vikings, another Viking off-spring, Duke William of Normandy, would successfully invade England using Viking-designed warships and transports, defeating Godwinson and his Huscarls using stirrup-stabilized cavalry at the battle of Hastings, becoming King William I of England (r.1066-1087) and ending the Viking Age.

Suggested Readings:

Primary sources

Friis-Jensen, Karsten, and Peter Fisher, eds. Gesta Danorum. Oxford Medieval Texts, 2015.

The Sagas of Ragnar Lodbrok.  Translated by Ben Waggoner. Troth Publications, 2009.

Secondary sources

Devries, Kelly. The Norwegian Invasion of England in 1066. Boydell & Brewer, 2003.

Griffith, Paddy. The Viking Art of War. Greenhill Books, 1995.

Sawyer, Peter. The Oxford Illustrated History of the Vikings. Oxford University Press, 2001.