He didn't defend them, he defeated them, and after he became assumed the throne of the Persian Empire he incorporated them into his own army.
He captured the eastern Mediterranean ports to eliminate the Persian navy threat and then defeated the Persian armies.
He captured the eastern Mediterranean ports to eliminate the Persian navy threat and then defeated the Persian armies.
Alexander the Great and his Macedonians defeated the Persian armies of Darius III at Gaugamela.
Alexander the Great defeated numerous great armies during his conquests. Some of the notable victories include the defeat of the Persian Empire led by Darius III at the Battle of Gaugamela, the conquest of the Egyptian and Persian forces at the Battle of Issus, and the defeat of the Indian army led by King Porus at the Battle of Hydaspes. These victories solidified Alexander's status as one of history's greatest military commanders.
Alexander the Great defeated the Persian empire
Cyrus the Great Darius the Great.
Alexander conquered the Persian Empire.
Alexander the Great was born a century after the end of the Persian War.
Alexander The Great
It was not easy, taking ten methodical years to do. He captured the eastern Mediterranean ports to eliminate the Persian navy threat to Macedonia and Greece, and then defeated the Persian armies, then captured the outlying provinces to the east.
Alexander the Great's conquest of the Persian Empire created an empire reaching from Egypt to India.
Alexander the Great conquered it. Upon his death, it eventually went to one of his generals. Then it was conquered by Rome, by the Mongols, and by Muslim armies. It is now called Iran.