Which two empires ruled at the same time for a few years ?

Empire of Japan: minimum 1743 years to date (see above)

Byzantine Empire: 874 years (uninterrupted from 330 to 1204)

Holy Roman Empire: 844 years (962-1806)

Zhou Empire: 790 years (1046–256 BCE)

Ethiopian Empire: 666 years (1270-1936)

Khmer Empire: 629 years (802–1431)

I hope this helped :)

the china one is last

explanation:

the map that was shown mostly had eastern asia highlighted. the answer would mostly likely be "the spread of communism into eastern asia set the stage for the korean war."

hopefully this .