The Varangians (//; Old Norse: Væringjar; Greek: Βάραγγοι, Várangoi, Βαριάγοι, Variágoi) was the name given by Greeks, Rus' people, Ruthenians and others to Vikings, who between the 9th and 11th centuries, ruled the medieval state of Kievan Rus', settled among many territories of modern Belarus, Russia and Ukraine, and formed the Byzantine Varangian Guard. According to the 12th century Kievan Primary Chronicle, a group of Varangians known as the Rus' settled in Novgorod in 862 under the leadership of Rurik. Before Rurik, the Rus' might have ruled an earlier hypothetical polity. Rurik's relative Oleg conquered Kiev in 882 and established the state of Kievan Rus', which was later ruled by Rurik's descendants.
Engaging in trade, piracy, and mercenary activities, Varangians roamed the river systems and portages of Gardariki, as the areas north of the Black Sea were known in the Norse sagas. They controlled the Volga trade route (between the Varangians and the Arabs), connecting the Baltic to the Caspian Sea, and the Dnieper and Dniester trade route (between Varangians and the Greeks) leading to the Black Sea and Constantinople. Those were the critically important trade links at that time, connecting Medieval Europe with wealthy and developed Arab Caliphates and the Byzantine Empire; Most of the silver coinage in the West came from the East via those routes.
Attracted by the riches of Constantinople, the Varangian Rus' initiated a number of Rus'-Byzantine Wars, some of which resulted in advantageous trade treaties. At least from the early 10th century many Varangians served as mercenaries in the Byzantine Army, constituting the elite Varangian Guard (the personal bodyguards of Byzantine Emperors). Eventually most of them, both in Byzantium and in Eastern Europe, were converted from paganism to Orthodox Christianity, culminating in the Christianization of Kievan Rus' in 988. Coinciding with the general decline of the Viking Age, the influx of Scandinavians to Rus' stopped, and Varangians were gradually assimilated by East Slavs by the late 11th century.
Medieval Greek Βάραγγος Várangos and Old East Slavic Варягъ Varjagŭ (Old Church Slavonic Варѧгъ Varęgŭ) are derived from Old Norse væringi, originally a compound of vár 'pledge' or 'faith', and gengi 'companion', thus meaning 'sworn companion', 'confederate', extended to mean 'a foreigner who has taken service with a new lord by a treaty of fealty to him', or 'protégé'. Some scholars seem to assume a derivation from vár with the common suffix -ing. Yet, this suffix is inflected differently in Old Norse, and furthermore, the word is attested with -gangia and cognates in other Germanic languages in the Early Middle Ages, as in Old English wærgenga, Old Frankish wargengus and Langobardic waregang. The reduction of the second part of the word could be parallel to that seen in Old Norse foringi 'leader', correspondent to Old English foregenga and Gothic 𐍆𐌰𐌿𐍂𐌰𐌲𐌰𐌲𐌲𐌾𐌰 fauragaggja 'steward'.
The terms “Varangian” and “Rus” can sometimes be used interchangeably but there are slight differences between the two groups. Both refer to the peoples of Scandinavian descent who settled in the Dnieper-Volga region during and after the 8th century. The Varangians are a more clearly definable group. They were Scandinavians in Eastern Europe who were often associated with Byzantium and the Byzantine emperor’s Varangian Guard. These mercenaries were almost entirely men who either returned to their Scandinavian homeland or married into the local Slavic culture. The term “Rus” is more difficult to define. The Rus were more inclined to settle in towns with their families. The term “Rus” is sometimes used in primary sources to describe Slavic peoples as well as Scandinavians. Its definition becomes clearer later in the period when it developed from the name of a people to the name of a political entity and area of land. The confusion in the primary sources about the meaning of Rus' has led to arguments between scholars about whether Russia was named after a Scandinavian people or a Slavic people. These are grouped into Normanist and anti-Normanist views (with the broader meaning of Norman, i.e. 'Norse-men'). Current scholarship supports the Normanist argument – that the Rus were a primarily Scandinavian people – but there have been heated debates in the last century between certain scholars fueled by nationalism. It is now generally accepted that the Rus' were of Scandinavian origin but adopted Slavic cultural characteristics fairly quickly.
Having settled Aldeigja (Ladoga) in the 750s, Scandinavian colonists played an important role in the early ethnogenesis of the Rus' people and in the formation of the Rus' Khaganate. The Varangians (Varyags in Old East Slavic) are first mentioned by the Primary Chronicle as having exacted tribute from the Slavic and Finnic tribes in 859. The Vikings were rapidly expanding in Northern Europe: England began to pay Danegeld (gold and other tribute to the Danish) in 859, and the Curonians of Grobin (in modern Latvia) faced an invasion by the Swedes around the same period. Due largely to geographic considerations, it is often argued that most of the Varangians who traveled and settled in the eastern Baltic, Russia, and lands to the south came from the area of modern Sweden.
In the 9th century, the Rus' operated the Volga trade route, which connected Northern Russia (Gardariki) with the Middle East (Serkland). The Volga route declined by the end of the century, and the Dnieper and Dniester routes rapidly overtook it in popularity. Apart from Ladoga and Novgorod, Gnyozdovo and Gotland were major centres for Varangian trade.