When Alexander became the King of Macedonia in 336 BC, he had no doubt in which direction he had to march his military for gaining glory: East. He did not think of marching into Western Europe. East was where all the fabulous cities were located. East was where he would go.
Tutored by Aristotle and other important teachers of Macedonia and Athens, Alexander knew about Herodotus’s glowing account of the wealth and splendor of Persia, and the grandeur of Egypt, which was conquered by the Persians in the 6th century BC. He knew about plays like The Bacchae (by Euripides), in which Dionysus says: “I have come to Greece from the fabulously wealthy East.” According to Dionysus, the lands of the East were dancing with the divine long before the Greeks.
Alexander knew about the reports of the travelers, sailors, traders, and military adventurers in which the fabulous treasures and culture of the East is described.
The “march eastwards” theme can be seen in the empire which inherited the legacy of Alexander and his general Seleucus I Nicator: Rome. The Romans did not become an empire when they established their control over much of Europe (which the Romans regarded as the land of barbarians) but when they turned their focus on Eastern Mediterranean, and under Emperor Augustus managed to conquer the great empire in the east, Egypt.
Cleopatra made a miscalculation when she got involved in a Roman civil war and decided to support the faction led by Mark Antony. When Antony’s forces were routed in the Battle of Actium in 30 BC, Augustus found the opportunity to bring his Roman troops to Egypt. Despite the fall of Mark Antony, Cleopatra had enough military strength to cause serious damage to the Roman forces. But she played a series of bad political moves and was outfoxed by Augustus.
Cleopatra committed suicide and the Romans became the masters of Egypt. Augustus had arrived in Egypt as a Roman general; he left as a Roman Emperor.