Viking Invasions

Viking expansion was the historical movement which led Norse explorers, traders and warriors, the latter known in modern scholarship as Vikings, to sail most of the North Atlantic, reaching south as far as North Africa and east as far as Russia, and through the Mediterranean as far as Constantinople and the Middle East, acting as looters, traders, colonists and mercenaries. To the west, Vikings under Leif Erikson, the heir to Erik the Red, reached North America and set up a short-lived settlement in present-day L'Anse aux Meadows, Newfoundland, Canada. Longer lasting and more established Norse settlements were formed in Greenland, Iceland, the Faroe Islands, Russia, Ukraine, Great Britain, Ireland, Normandy and Sicily.

Motivation for expansion

There is much debate among historians about what drove the Viking expansion.

Researchers have suggested that Vikings may have originally started sailing and raiding due to a need to seek out women from foreign lands. The concept was expressed in the 11th century by historian Dudo of Saint-Quentin in his semi-imaginary ''History of The Normans''. Rich and powerful Viking men tended to have many wives and concubines, and these polygynous relationships may have led to a shortage of eligible women for the average Viking male. Due to this, the average Viking man could have been forced to perform riskier actions to gain wealth and power to be able to find suitable women. Viking men would often buy or capture women and make them into their wives or concubines. Polygynous marriage increases male-male competition in society because it creates a pool of unmarried men who are willing to engage in risky status-elevating and sex-seeking behaviors. The ''Annals of Ulster'' states that in 821 the Vikings plundered an Irish village and "carried off a great number of women into captivity".

Raiding parties offered not only the opportunity for violence and wealth, but also the chance to be noticed by their peers and superiors. They offered the opportunity to build a reputation for skill, reliability, cunning, or courage. Just as raiding leaders had more to gain than just material wealth, their followers could also gain intangible social capital by participating.

Another theory is that it was a quest for revenge against continental Europeans for past aggressions against the Vikings and related groups, Charlemagne's campaign to force Saxon pagans to convert to Christianity by killing any who refused to become baptized in particular."Franques Royal Annals" cited in Peter Sawyer, ''The Oxford Illustrated History of the Vikings'', 2001, p. 20. Those who favor this explanation point out that the penetration of Christianity into Scandinavia caused serious conflict and divided Norway for almost a century. However, the first target of Viking raids was not the Frankish Kingdom, but Christian monasteries in England. According to the historian Peter Sawyer, these were raided because they were centers of wealth and their farms well-stocked, not because of any religious reasons.

A different idea is that the Viking population had exceeded the agricultural potential of their homeland. This may have been true of western Norway, where there were few reserves of land; however, it is unlikely that the rest of Scandinavia was experiencing famine.

Alternatively, some scholars propose that the Viking expansion was driven by a youth bulge effect: Because the eldest son of a family customarily inherited the family's entire estate, younger sons had to seek their fortune by emigrating or engaging in raids. Peter Sawyer suggests that most Vikings emigrated due to the attractiveness of owning more land rather than the necessity of having it.

However, no rise in population, youth bulge, or decline in agricultural production during this period has been definitively demonstrated. Nor is it clear why such pressures would have prompted expansion overseas rather than into the vast, uncultivated forest areas in the interior of the Scandinavian Peninsula, although perhaps emigration or sea raids may have been easier or more profitable than clearing large areas of forest for farm and pasture in a region with a limited growing season.

It is also possible that a decline in the profitability of old trade routes drove the Vikings to seek out new, more profitable ones. Trade between western Europe and the rest of Eurasia may have suffered after the Roman Empire lost its western provinces in the 5th century, and the expansion of Islam in the 7th century may have reduced trade opportunities within western Europe by redirecting resources along the Silk Road. Trade in the Mediterranean was at its lowest level in history when the Vikings began their expansion. The Viking expansion opened new trade routes in Arab and Frankish lands, and took control of trade markets previously dominated by the Frisians after the Franks destroyed the Frisian fleet.

One of the main aims of the Viking expansion throughout Europe was to acquire and trade silver. Bergen and Dublin are still important centres of silver making. An example of a collection of Viking-age silver for trading purposes is the Galloway Hoard. Pagans from Eastern Europe came to be the most popular targets for slavery in both the Byzantine Empire and the Islamic Arab world during the Early Middle Ages, where they were forced to convert to Christianity and Islam respectively after their enslavement.

The Vikings trafficked European slaves captured in Viking raids in Eastern Europe in two destinations from present day Russia via the Volga trade route; one to Slavery in the Abbasid Caliphate in the Middle East via the Caspian Sea, the Samanid slave trade and Iran; and one to the Byzantine Empire and the Mediterranean via Dnieper and the Black Sea slave trade. During the eighth to tenth centuries, slaves from Eastern Europe and the Baltic Sea were traded to elite households in Byzantium and the Islamic world via the Dnieper and Volga river systems, the Carolingian Empire and Venice. The slaves may have also been transported to Hedeby or Brännö and then transported through the Volga trade route to Russia, where slaves and furs were sold to Muslim merchants in exchange for Arab silver ''dirham'' and silk, which have been found in Birka, Wollin and Dublin; initially this trade route between Europe and the Abbasid Caliphate passed via the Khazar Khaganate, but from the early 10th-century onward it went via Volga Bulgaria and from there by caravan to Khwarazm, to the Samanid slave market in Central Asia and finally via Iran to the Abbasid Caliphate.

One of the reasons Kievan Rus came to be was that Scandinavian settlers established themselves and traded with captured slaves. Arabic merchants from the Caspian Sea and Byzantine merchants from the Black Sea brought their goods to the trade markets in Rus, where they met the Viking traders and warriors known as Varangians