c350 The Huns push from the east as far as the Volga.
by 362 The Ostrogoths reputedly rule an empire under King Ermanarich (Herman) that covers not only the Pontic steppe, but reaches back to their homeland on the Baltic.
The Slav territories expand to the cost of the Balts, and the Finns move into their present-day homeland.
The New Penguin Atlas of Medieval History, Colin McEvedy, pp 10-11
Should the Bosporan Kingdom appear on the map? Wikipedia says: With the coins of the last king Rhescuporis VI in 341, constructing a chronology becomes very difficult. The kingdom was probably finally overrun by the Huns, who defeated the nearby Alans in 375/376 and moved rapidly westwards towards the Roman empire.