Until the eighth century, the Scandinavian region was on the periphery of European trade, and Scandinavians (the Norse) themselves did not greatly influence the people of neighboring regions. Scandinavian tribesmen had long traded amber (petrified sap, prized as a precious stone in Rome and, subsequently, throughout the Middle Ages) with both other Germanic tribes and even with the Romans directly during the imperial period. While the details are unclear, what seems to have happened is that sometime around 700 CE the Baltic Sea region became increasingly economically significant. Traders from elsewhere in Northern Europe actively sought out Baltic goods like furs, timber, fish, and (as before) amber. This created an ongoing flow of wealth coming in to Scandinavia, which in turn led to Norse leaders becoming interested in the sources of that wealth. At the same time, the Norse added sails to their unique sailing vessels, longships. Sailed longships allowed the Norse to travel swiftly across the Baltic, and ultimately across and throughout the waterways of Europe.
The Norse, soon known as Vikings, exploded into the consciousness of other Europeans during the eighth century, attacking unprotected Christian monasteries in the 790s, with the first major raid in 793 and follow-up attacks over the next two years. The Vikings swiftly became the great naval power of Europe at the time. In the early years of the Vikings period they tended to strike in small raiding parties, relying on swiftness and stealth to pillage monasteries and settlements. As the decades went on, bands of raiders gave way to full-scale invasion forces, numbering in the hundreds of ships and thousands of warriors. They went in search of riches of all kinds, but especially silver, which was their standard of wealth, and slaves, who were equally lucrative. Unfortunately for the monks of Europe, silver was most often used in sacred objects in monasteries, making the monasteries the favorite targets of Viking raiders. The raids were so sudden and so destructive that Charlemagne himself ordered the construction of fortifications at the mouth of the Seine river and began expanding his naval defenses to try to defend against them.
The word "Viking" was used by the Vikings themselves – it either meant “raider” or was a reference to the Vik region that spanned parts of Norway and Sweden. They were known by various other names by the people they raided, from the Middle East to France: the Franks called them “pagani” or “Northmen,” the Anglo-Saxons “haethene men,” the Arabs “al-Majus” (sorcerers), the Germanic tribes “ascomanni” (shipmen), and the Slavs of what would become Russia the “Rus” or “Varangians” (the latter are described below.) Outside of the lands that would eventually become Russia, the Vikings were universally regarded as a terrifying threat, not least because of their staunch paganism and rapacious treatment of Christians.
At their height, the Vikings fielded huge fleets that raided many of the major cities of early medieval Europe and North Africa. By the late ninth century they were formally organized into a “Great Fleet” based in their kingdom in eastern England (they conquered the Anglo-Saxon kingdom of East Anglia in the 870s). While the precise numbers will never be known, not least because the surviving sources bear a pronounced anti-Viking bias, it is clear that their raids were on scale that dwarfed their earlier efforts. In 844 more than 150 ships sailed up the Garonne River in southern France, plundering settlements along the way. In 845, 800 ships forced the city of Hamburg in northern Germany to pay a huge ransom of silver. In 881, the Great Fleet pillaged across present-day Holland, raiding inland as far as Charlemagne’s capital of Aachen and sacking it. Then, in 885, at least 700 ships sailed up the Seine River and besieged Paris (note that their initial target, a rich monastery, had evacuated with its treasure; the wine cellar was not spared, however). In this attack, they extorted thousands of pounds of silver and gold. Vikings attacked Constantinople at least three times in the ninth and tenth centuries, extracting tribute and concessions in trade, and perhaps most importantly, they came to rule over what would one day become Russia. In the end, the Vikings became increasingly knowledgeable about the places they were raiding, in some cases actually working as mercenaries for kings who hired them to defend against other Vikings.
Starting in roughly 850 CE, the Vikings started to settle in the lands they raided, especially in England, the hitherto-uninhabited island of Iceland, and part of France. Their most important settlement in terms of its historical impact was Normandy in what is today northern France, a kingdom that would go on centuries later to conquer England itself. It was founded in 911 as a land-grant to the Viking king Rollo in order to defend against other Vikings. Likewise, the Vikings settled areas in England that would help shape the English language and literary traditions (for example, though written in the language of the Anglo-Saxons, the famous epic poem Beowulf is about Viking settlers who had recently converted to Christianity). Ultimately, the Vikings became so rich from raiding that they became important figures in medieval trade and commerce, trading goods as far from Scandinavia as Baghdad in the Abbasid Caliphate.
The Vikings were not just raiders, however. They sought to explore and settle in lands that were in some cases completely uninhabited when they arrived, like Iceland. They appear to have been fearless in quite literally going where no one had gone before. Much of their exploration required audacity as well as planning - they were the best navigators of their age, but at times their travels led them to forge into areas completely unknown to Europeans. Vikings were the first Europeans to arrive in North America, with group of Icelandic Vikings arriving in Newfoundland, in present-day Canada, around the start of the eleventh century. An attempt at colonization failed, however, quite possibly because of a conflict between the Vikings and the indigenous people they encountered, and the people of the Americas were thus spared the presence of further European colonists for almost five more centuries.
In what eventually became Russia, meanwhile, Viking exploration, conquest, and colonization had begun even earlier. The Vikings started traveling down Russian rivers from the Baltic in the mid-eighth century, even before the raiding period began farther west. Their initial motive was trade, not conquest, trading and collecting goods like furs, amber, and honey and transporting them south to both Byzantium and the Abbasid Caliphate. The Vikings were slavers as well, capturing Slavic peoples and selling them in the south. In turn, the Vikings brought a great deal of Byzantine and Abbasid currency to the north, introducing hard cash into the mostly barter-based economies of Northern and Western Europe. Eventually, they settled along their trade routes, often invited to establish order by the native Slavs in cities like Kiev, with the Vikings ultimately forming the earliest nucleus of Russia as a political entity. The very name “Russia” derives from “Rus,” the name of the specific Viking people (originally from Sweden) who settled in the Slavic lands bordering Byzantium.
As the Vikings settled in the lands they had formerly raided and as powerful states emerged in Scandinavia itself, the Vikings ceased being raiders and came to resemble other medieval Europeans. By the mid-tenth century, the kings of the Scandinavian lands began to assert their control and to reign in Viking raids. Conversion to Christianity, becoming very common by 1000, helped end the raiding period as well. Denmark became a stable kingdom under its king Harald Bluetooth in 958, Norway in 995 under Olaf Tryggvason, and Sweden in 995 as well under Olof Skötkonung. Meanwhile, in northern France, the kingdom of Normandy emerged as the most powerful of the former Viking states, with its duke William the Conqueror conquering England itself from the Anglo-Saxons in 1066.