The question is incomplete but I will provide the right answers:
Russia's Invaders came from the territory labeled A. - Scandinavia, more specifically modern-day Sweden. These invaders were eastern Vikings who raided the Baltic Coast, Finland, the Baltic States, and settled in modern-day Ukraine and Russia.
They establish the city of kiev, located at E. - Kiev is the current capital of Ukraine, and is located along the Dnieper River, in the middle of a very fertile plain. When the Vikings first arrived in the area, the founded the city to serve as the center of a new state: the Kievan 'Rus (hence the name).
Kiev's important trading partner, Constantinople, located at F. - Constantinople correspond to Istanbul, the capital of Turkey. They are the same city, but the Turks changed its name when they conquered the place in 1453. Constantinople location straddles the Strait of Bosphorus, which divides Anatolia (Asia), from Thrace (Europe). It is an strategic location because it connects the Mediterranean and the Black Seas.
