What two civilizations are regarded as the earliest roots of Europe's government systems?

The Greek and Roman societies

Explanation:

The two classic examples of European roots are commonly known to be Ancient Greece and Rome. The Greeks are the historical foundation of democracy, but not how we understand it to be used in today's world, but to limit the possibility of an uprising of the aristocracy again. They used an oligarchy system which held power in the hands of a few not just a single individual, but all citizens had equal rights to be heard in assembly (citizens were primarily white men or the head man of the home, not slaves or metics which were non natives living there) The other major influence or root of government was the Roman civilization, which has a large impact in becoming the first "Imperial-city" and the legacy of law which is seen in the terminology of modern law as well as use of ancient laws in current cases. (example is the right to return a defective product under warranty, then was used for slaves and animal purchases)