Colonization of Iceland by Norwegian Vikings began in the ninth century. The first source that Iceland and Greenland appear in is a papal letter of 1053. Twenty years later, they are then seen in the Gesta of Adam of Bremen. It was not until after 1130, when the islands had become Christianized, that accounts of the history of the islands were written from the point of view of the inhabitants in sagas and chronicles. The Vikings explored the northern islands and coasts of the North Atlantic, ventured south to North Africa and east to Russia, Constantinople, and the Middle East. They raided and pillaged, traded, acted as mercenaries and settled wide-ranging colonies. Early Vikings probably returned home after their raids. Later in their history, they began to settle in other lands. Vikings under Leif Ericson, heir to Erik the Red, reached North America and set up short-lived settlements in present-day L'Anse aux Meadows, Newfoundland, Canada. This expansion occurred during the Medieval Warm Period.
Viking expansion into continental Europe was limited. Their realm was bordered by powerful cultures to the south. Early on, it was the Saxons, who occupied Old Saxony, located in what is now Northern Germany. The Saxons were a fierce and powerful people and were often in conflict with the Vikings. To counter the Saxon aggression and solidify their own presence, the Danes constructed the huge defence fortification of Danevirke in and around Hedeby. The Vikings soon witnessed the violent subduing of the Saxons by Charlemagne, in the thirty-year Saxon Wars in 772�804. The Saxon defeat resulted in their forced christening and the absorption of Old Saxony into the Carolingian Empire. Fear of the Franks led the Vikings to further expand Danevirke, and the defence constructions remained in use throughout the Viking Age and even up until 1864. The south coast of the Baltic Sea was ruled by the Obotrites, a federation of Slavic tribes loyal to the Carolingians and later the Frankish empire. The Vikings�led by King Gudfred�destroyed the Obotrite city of Reric on the southern Baltic coast in 808 AD and transferred the merchants and traders to Hedeby. This secured their supremacy in the Baltic Sea, which remained throughout the Viking Age.
Facilitated by advanced sailing and navigational skills, and characterised by the longship, Viking activities at times also extended into the Mediterranean littoral, North Africa, the Middle East and Central Asia. Following extended phases of (primarily sea- or river-borne) exploration, expansion and settlement, Viking communities and governments were established in diverse areas of north-western Europe, Belarus, Ukraine and European Russia, the North Atlantic islands and as far as the north-eastern coast of North America. This period of expansion witnessed the wider dissemination of Norse culture, while simultaneously introducing strong foreign cultural influences into Scandinavia itself, with profound developmental implications in both directions.
Popular, modern conceptions of the Vikings�the term frequently applied casually to their modern descendants and the inhabitants of modern Scandinavia�often strongly differ from the complex picture that emerges from archaeology and historical sources. A romanticised picture of Vikings as noble savages began to emerge in the 18th century; this developed and became widely propagated during the 19th-century Viking revival. Perceived views of the Vikings as alternatively violent, piratical heathens or as intrepid adventurers owe much to conflicting varieties of the modern Viking myth that had taken shape by the early 20th century. Current popular representations of the Vikings are typically based on cultural clich�s and stereotypes, complicating modern appreciation of the Viking legacy. These representations are not always accurate � for example, there is no evidence that they wore horned helmets.
The period from the earliest recorded raids in the 790s until the Norman conquest of England in 1066 is commonly known as the Viking Age of Scandinavian history. Vikings used the Norwegian Sea and Baltic Sea for sea routes to the south. The Normans were descended from Vikings who were given feudal overlordship of areas in northern France�the Duchy of Normandy�in the 10th century. In that respect, descendants of the Vikings continued to have an influence in northern Europe. Likewise, King Harold Godwinson, the last Anglo-Saxon king of England, had Danish ancestors. Two Vikings even ascended to the throne of England, with Sweyn Forkbeard claiming the English throne in 1013�1014 and his son Cnut the Great becoming king of England 1016�1035.
Geographically, a Viking Age may be assigned to not only Scandinavian lands (modern Denmark, Norway and Sweden), but also territories under North Germanic dominance, mainly the Danelaw, including Scandinavian York, the administrative centre of the remains of the Kingdom of Northumbria, parts of Mercia, and East Anglia. Viking navigators opened the road to new lands to the north, west and east, resulting in the foundation of independent settlements in the Shetland, Orkney, and Faroe Islands; Iceland; Greenland; and L'Anse aux Meadows, a short-lived settlement in Newfoundland, circa 1000. The Greenland settlement was established around 980, during the Medieval Warm Period, and its demise by the mid-15th century may have been partly due to climate change. The Viking Rurik dynasty took control of territories in Slavic and Finno-Ugric-dominated areas of Eastern Europe; they annexed Kiev in 882 to serve as the capital of the Kievan Rus'.
As early as 839, when Swedish emissaries are first known to have visited Byzantium, Scandinavians served as mercenaries in the service of the Byzantine Empire. In the late 10th century, a new unit of the imperial bodyguard formed. Traditionally containing large numbers of Scandinavians, it was known as the Varangian Guard. The word Varangian may have originated in Old Norse, but in Slavic and Greek it could refer either to Scandinavians or Franks. The most eminent Scandinavian to serve in the Varangian Guard was Harald Hardrada, who subsequently established himself as king of Norway (1047�1066).
An emperor of the Byzantine Empire is guarded by two Vikings with spear. From the Chronicle of John Skylitzes. There is archaeological evidence that Vikings reached Baghdad, the centre of the Islamic Empire. The Norse regularly plied the Volga with their trade goods: furs, tusks, seal fat for boat sealant, and slaves. Important trading ports during the period include Birka, Hedeby, Kaupang, Jorvik, Staraya Ladoga, Novgorod, and Kiev.
Generally speaking, the Norwegians expanded to the north and west to places such as Ireland, Scotland, Iceland, and Greenland; the Danes to England and France, settling in the Danelaw and Normandy; and the Swedes to the east, founding Kievan Rus'. Among the Swedish runestones mentioning expeditions overseas, almost half tell of raids and travels to western Europe. According to the Icelandic sagas, many Norwegian Vikings also went to eastern Europe. In the Viking Age, the present day nations of Norway, Sweden and Denmark did not exist, but were largely homogeneous and similar in culture and language, although somewhat distinct geographically. The names of Scandinavian kings are reliably known only for the later part of the Viking Age. After the end of the Viking Age the separate kingdoms gradually acquired distinct identities as nations, which went hand-in-hand with their Christianisation. Thus the end of the Viking Age for the Scandinavians also marks the start of their relatively brief Middle Ages.
The motives driving the Viking expansion are a topic of much debate in Nordic history. One common theory posits that Charlemagne "used force and terror to Christianise all pagans", leading to baptism, conversion or execution, and as a result, Vikings and other pagans resisted and wanted revenge. The penetration of Christianity into Scandinavia led to serious conflict dividing Norway for almost a century.
Another explanation is that the Vikings exploited a moment of weakness in the surrounding regions. England suffered from internal divisions and was relatively easy prey given the proximity of many towns to the sea or to navigable rivers. Lack of organised naval opposition throughout Western Europe allowed Viking ships to travel freely, raiding or trading as opportunity permitted. The decline in the profitability of old trade routes could also have played a role. Trade between western Europe and the rest of Eurasia suffered a severe blow when the Roman Empire fell in the 5th century. The expansion of Islam in the 7th century had also affected trade with western Europe.
Raids in Europe, including raids and settlements from Scandinavia, were not unprecedented and had occurred long before the Vikings arrived. The Jutes invaded the British Isles three centuries earlier, pouring out from Jutland during the Age of Migrations, before the Danes settled there. The Saxons and the Angles did the same, embarking from mainland Europe. The Viking raids were, however, the first to be documented in writing by eyewitnesses, and they were much larger in scale and frequency than in previous times.
Vikings themselves were expanding; although their motives are unclear, historians believe that scarce resources were a factor.
The "Highway of Slaves" was a term used to describe a route that the Vikings found to have a direct pathway from Scandinavia to Constantinople and Baghdad while traveling on the Baltic Sea. With the advancements of their ships during the ninth century, the Vikings were able to sail to Russia and some northern parts of Europe.
During the Viking Age, Scandinavian men and women traveled to many parts of Europe and beyond, in a cultural diaspora that left its traces from Newfoundland to Byzantium. This period of energetic activity also had a pronounced effect in the Scandinavian homelands, which were subject to a variety of new influences. In the 300 years from the late 8th century, when contemporary chroniclers first commented on the appearance of Viking raiders, to the end of the 11th century, Scandinavia underwent profound cultural changes.
By the late 11th century, royal dynasties legitimised by the Catholic Church (which had had little influence in Scandinavia 300 years earlier) were asserting their power with increasing authority and ambition, and the three kingdoms of Denmark, Norway, and Sweden had taken shape. Towns appeared that functioned as secular and ecclesiastical administrative centres and market sites, and monetary economies began to emerge based on English and German models. By this time the influx of Islamic silver from the East had been absent for more than a century, and the flow of English silver had come to an end in the mid-11th century. Christianity had taken root in Denmark and Norway with the establishment of dioceses during the 11th century, and the new religion was beginning to organise and assert itself more effectively in Sweden. Foreign churchmen and native elites were energetic in furthering the interests of Christianity, which was now no longer operating only on a missionary footing, and old ideologies and lifestyles were transforming. By 1103, the first archbishopric was founded in Scandinavia, at Lund, Scania, then part of Denmark.
The assimilation of the nascent Scandinavian kingdoms into the cultural mainstream of European Christendom altered the aspirations of Scandinavian rulers and of Scandinavians able to travel overseas, and changed their relations with their neighbours. One of the primary sources of profit for the Vikings had been slave-taking. The medieval Church held that Christians should not own fellow Christians as slaves, so chattel slavery diminished as a practice throughout northern Europe. This took much of the economic incentive out of raiding, though sporadic slaving activity continued into the 11th century. Scandinavian predation in Christian lands around the North and Irish Seas diminished markedly.
The kings of Norway continued to assert power in parts of northern Britain and Ireland, and raids continued into the 12th century, but the military ambitions of Scandinavian rulers were now directed toward new paths. In 1107, Sigurd I of Norway sailed for the eastern Mediterranean with Norwegian crusaders to fight for the newly established Kingdom of Jerusalem, and Danes and Swedes participated energetically in the Baltic Crusades of the 12th and 13th centuries.
