How was Alexander the Great able to am his empire?

He conquered all of the known world in his day. Born in Macedonia, he began running it at the age of 16. At 17 he joined his father (King Philip) and soon took one of the armies and defeated Thebes. He conquered all that you mentioned and was ready to conqueror the Arabian peninsula at the age of 33. but died of a fever. Napoleon during his empire building is compared with Alexander.