By first absorbing Media, and then using the combined strength to progressively take over the Babylonian and Lydian Empires, then expand to include all of the Middle East, Central Asia and Egypt-Libya.
Yes.
darius used some of persian's great wealth to build roads across the empire
He built the Royal Roads
He didn't build any empire - he simply stole the Persian Empire and made it into his own.
The governing system of the Persian Empire, resting on traditional local government, provincial government and central imperial government.
He began in 549 BCE until his death in 529 BCE.
The Persian Empire.
The Persian Empire was not a person.
Persian Empire
The Persian Empire absorbed the Babylonian Empire.
Alexander the Great defeated the Persian empire
The Persian Empire absorbed the Baabylonian Empire.