Well, Moscow didn't even exist in the 9th century. It grew up during the Mongols' 13th century reign by playing footsie with the Khans, and started expanding into its neighbours territory when the Golden Horde began to dissolve, about the end of the 14th. After knocking over the other cities in the forest zone, the first big conquest was the city of Kazan, on the Volga, which by then had been a sedentary population of mostly Turkic peoples (Tatars) for a hundred years or more. That was 1552. It is still about half Tatar, and Muslim.
From around A.D. 800 to the 11th century, a vast number of Scandinavians left their homelands to seek their fortunes elsewhere. These seafaring warriors–known collectively as Vikings or Norsemen (“Northmen”)–began by raiding coastal sites, especially undefended monasteries, in the British Isles. Over the next three centuries, they would leave their mark as pirates, raiders, traders and settlers on much of Britain and the European continent, as well as parts of modern-day Russia, Iceland, Greenland and Newfoundland.
To do that they had to settle there so they were and became tribes of people living in Russia that were preying on others around them.
By the tenth century, the northern part of the East European Plain and its Baltic and White Sea coasts were settled by tribes of East Slavic, Baltic, and Finnic peoples. The first historical exploration of the region was conducted by Norse Varangians, who established the principalities of Rus. After the dissolution of that polity, the Grand Duchy of Moscow would eventually collect most of the lands of European Russia starting from the 13th century.
wy69