Ruins of the Hvalsey Church at Hvalsey, GreenlandThe Swedes were particularly active in Eastern Europe, where they were known as the Rus' .[71][22] They
were engaged in extensive trade with the Byzantine Empire and the Abbasid Caliphate,
launching raids on Constantinople and expeditions in the Caspian Sea.[85] The Rus' are described in detail
by the Arab traveller Ahmad ibn Fadlan, who described them as tall, blond and the most "perfect
physical specimens" he had ever seen.[87] In the 9th century, the Viking Rurik is believed to have founded
the Rurik dynasty, which eventually developed into Kievan Rus'. The North Germanic elite of this state
were known as the Rus'. In the 10th century, the Rus', in cooperation with surviving Crimean Goths,
destroyed the Khazar Khaganate and emerged as the dominant power in Eastern Europe.[88] By the 11th
century, the Rus' had converted to Eastern Orthodoxy and were gradually merging with the local East
Slavic population, becoming known as the Russians.[22][85] The North Germanic diaspora in the area were
thereafter called Varangians.[7] Many of them served in the Varangian Guard, the personal bodyguard of
the Byzantine emperors.[71] Among the prominent Scandinavians who served in the Varangian Guard
were Norwegian king Harald Hardrada.[22][85]
While the Danes and Swedes were active in Francia and Russia respectively, North Germanic tribes from
Norway were actively exploring the North Atlantic.[71] These Vikings were the first sailors in naval history
to venture out into the open sea.[89] This initially resulted in the colonization of the Shetland
Islands, Orkney Islands, the Faroese Islands and Iceland.[7] The most important Norse colony was the
settlement in Iceland, which became a haven for Scandinavians who sought to preserve their traditional
way of life and independence of central authority.[90] The literary heritage of the Icelanders is
indispensable for the modern understanding of early North Germanic history and culture.[91] In the late
10th century, the Icelandic explorer Erik the Red discovered Greenland and supervised the
Norse settlement of the Iceland.[85] His son Leif later made the first documented trans-oceanic voyage in
history and thereafter supervised the attempted Norse colonization of North America.[92]