And it all comes from the same genetic pool.
If you go into Aya Sophia you can see the graphiti carved into the stone and it is all Runic or Viking script.
I quote from The Russians by Robin Miller-Gulland
The origins of the Rus were the Varangians or vikings. The name Rus derives from the Germanic Scandinavian word Rod which means to row. There are a number of other quotes and if you are interested there are several other books that substantiate this. Varangian was also another term for viking. It is quite possible that one of the reasons that Russia adopted Greek Orthodox was the religion travelling back to Moscow when Varangian soldiers returned to Russia. Russian orthodoxy goes back to 945 when St Cyril was active with the Kievan Rus. The Rus were Varangian and the Varangian were Viking. Varangian colonies
The Varangians or Varyags (Old Norse: Væringjar; Greek: Βάραγγοι, Βαριάγοι, Varangoi, Variagoi; Russian and Ukrainian: Варяги, Varyagi / Varyahy ), sometimes referred to as Variagians, were Vikings who went eastwards and southwards through what is now Russia, Belarus and Ukraine mainly in the 9th and 10th centuries.
Having settled Aldeigja (Ladoga) in the 750s, Scandinavian colonists were probably an element in the early ethnogenesis of the Rus' people, and likely played a role 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. It was the time of rapid expansion of the Vikings in Northern Europe; England began to pay Danegeld in 859, and the Curonians of Grobin faced an invasion by the Swedes at about the same date.
According to the Primary Chronicle, in 862, the Finnic and Slavic tribes rebelled against the Varangian Rus, driving them overseas back to Scandinavia, but soon started to conflict with each other. The disorder prompted the tribes to invite back the Varangian Rus "to come and rule them" and bring peace to the region. Led by Rurik and his brothers Truvor and Sineus, the invited Varangians (called Rus) settled around the town of Holmgård (Novgorod).
In the 9th century, the Rus' operated the Volga trade route, which connected Northern Russia (Gardariki) with the Middle East (Serkland). As the Volga route declined by the end of the century, the trade route from the Varangians to the Greeks rapidly overtook it in popularity. Apart from Ladoga and Novgorod, Gnezdovo and Gotland were major centres for Varangian trade.
Western historians tend to agree with the Primary Chronicle that these Varangians organized the existing Slavic settlements into the political entity of Kievan Rus' in the 880s and gave their name to the land. Many Slavic scholars are opposed to this theory of Germanic influence on the Rus' (people) and have suggested alternative scenarios for this part of Eastern European history because the author of the Primary Chronicles, that is a monk named Nestor, worked in the court for the Varangians.