A tribe known as the "Sacae" migrated east of Sumer. They spoke a language that was the root of all Ural-Altaic languages (Finnish, Hungarian, Mongolian, Japanese, etc.). They branched to the fareast and became the Japanese and Eskimos. The Sacae later migrated northwest to Ukraine and became the Scythians.
The Nordic Indo-Europeans settled in Scythia and gave them the Iranian language. They migrated westward. One branch became the Slavs and Scandinavians. Another branch became the Saxons and Scots.