Answer: Vikings and Byzantines
Step-by-step explanation:
The famous Vikings who as a result of the Norman conquests of England, have a heavy influence on the ancestry of the English, also have a heavy influence on Russia as well.
Vikings were traders and explorers (along with raiding) and in some of their trips they encountered the Slavic people of Eastern Europe. Overtime they intermarried and their descendants became Russians.
The Byzantines also had a heavy influence on Russian ancestry because the Byzantines were in Eastern Europe. They encountered the Slavic people as well and spread Orthodox Christianity to them as well as intermarrying and integrating them into their culture.