Alexander III of Macedon, or'Alexander the Great' as he came to be known, was perhaps the best conqueror of the ancient world. By the time of his death in 323 BC, he'd managed to subdue a large portion of the known world, and his empire stretched from the Aegean from the west to India in the east, and from Macedonia in the north to Egypt in the south.
Alexander's conquest helped spread influence throughout the ancient Near East, where this influence was felt most keenly, though was only the upper echelons of society, and people carried on as usual. In Egypt, control would be seized by Alexander's general Ptolemy, and he and his descendants were depicted in art. Greek became the lingua franca throughout much of the former empire of Alexander, even after the Romans conquered most of it.
The effect of Alexander can be traced in other things. By way of example, in Classical Greece, in the fifth and fourth centuries BC, it was apparently common for young men to be clean-shaven and have their hair cropped short, whereas older men (at least, among those who had been comparatively wealthy), wore their hair long and had beards. Alexander chose to be having his hair and clean-shaven short, but not cropped.
Other men and women emulated the style. Depictions of Alexander the Great -- as figurines, on coins, and so on -- were commonplace. Other Alexander the Great (2016) art print for sale virtosuart.com Hellenistic rulers often sought to copy Alexander not just in actions, but also in appearance (coins of Ptolemy depict him clean-shaven and with relatively short hair).
And let us take a look at this marble head in Rhodes in the museum:
Like Alexander, right? Except that this is actually the head of the sun god Helios, dated to the Middle Hellenistic period. It perhaps was part of the pediment of his temple. We know it isn't Alexander since there are holes around the periphery of the cranium where the metal beams of his crown would have been inserted (these represented the rays of the sun).
Portrayals in this style emulate the work of Lysippus, Alexander's personal sculptor. It is a testament to the deeds of Alexander that his features were deemed appropriate for producing pictures of the gods to be utilized as the template. But then, hadn't Alexander himself been declared a god by the Oracle of Ammon at Siwa after he had conquered Egypt (at least, according to some interpretations of Arr. Anab. 3.4.5; cf. 4.9.9)?