The Varangians (Varyags, in Russian spelling) are first mentioned by the Russian Primary Chronicle as having arrived from beyond the Baltic Sea around the mid-9th century, invited by the warring Slavic tribes to bring peace to the region (these Slavic and Finnish tribes had chased away the first Scandinavian settlers). They were led by Rurik and his two brothers Askold and Dir, who settled around the Slavic village of Novgorod. These early Varangians were likely legendary, but a real Swedish settlement, Aldeigjuborg, was established around Lake Ladoga in the 8th century.
The Slavic inhabitants called these Swedes "Rus'," which is probably derived from an Old Norse term for "the men who row," signifying their maritime heritage. Another term for them was Varangian, which was likely derived from words meaning "those who swear oaths," and came to specifically denote Scandinavian mercenaries from the areas controlled by the Rus'.
The Varangian Guard
Varangians first appear in the Byzantine world in 839, when the emperor Theophilus II negotiated with them to provide a few mercenaries for his army. Although the Rus' often had peaceful trading relations with the Byzantines, Varangian raiders sometimes attacked from the north. Such attacks came in 860, 907, 911, 941, 945, 971, and finally 1043. These raids were successful only in causing the Byzantines to re-arrange their trade treaties; militarily, they were always defeated by the superior Byzantines, especially by the use of Greek fire.
The ruling class of the two powerful city-states of Novgorod and Kiev eventually became Varangian, and the Byzantines soon acquired an official mercenary force that became the Varangian Guard. This occurred in 988, when Kievan Prince Vladimir the Great converted to Orthodox Christianity. In exchange for a marriage to Basil II's sister Anna, Vladimir gave Basil 6000 Varangians to use as his own personal bodyguard. The Varangian Guard was one of the fiercest and most loyal elements of the Byzantine army, as described in Anna Comnena's chronicle of the reign of her father Alexius I, the Alexiad. Their main weapon was a long axe, although they could also be used as swordsmen or archers. They were the only element of the army to successfully defend part of Constantinople during the Fourth Crusade, although the Guard was apparently disbanded after the city's capture in 1204. By this time, the term Varangian referred to any mercenary from northern Europe, and the Guard was probably composed more of English and Scottish mercenaries than Russians or Scandinavians.
One of the most famous members of the Varangian Guard was the future king Harald III of Norway, also known as Harald Hadrada, who arrived in Constantinople in 1035. He participated in eighteen battles and became Akolythos, the commander, of the Guard before returning home in 1043.
In contrast to the intense Viking influence in Normandy and the British Isles, Varangian culture did not survive to a great extent in the east. Instead, it rapidly assimilated to the Slavic substrate.