 Complete the following phrase:  Scandinavian Norsemen, known as Vikings in Western Europe and Varangians in the East, combined piracy and trade throughout Northern Europe. In the mid-9th century, they began to venture along the waterways from the eastern Baltic to the Black and Caspian Seas. According to the earliest Russian chronicle, a Varangian named Rurik was elected ruler knyaz of Novgorod in about 860, before his successors moved south and extended their authority to Kiev, which had been previously dominated by the Khazars. Oleg, Ruriks son Igor and Igors son Sviatoslav subsequently subdued all local East Slavic tribes to Kievan rule, destroyed the Khazar Khaganate and launched several military expeditions to Byzantium and 