When did the nomads flourish?

2 million years ago

federal power is further limited with a system of checks and balances that gives each branch of government a measure of power over the others.

explanation:

in 550 b.c.e. cyrus the great, the leader of the persians, conquered the medes and united the iranian people under one ruler for the first time. cyrus became the first king of the persian empire and went on to establish one of the largest empires in world.