The most interesting, as well as the most important, feature of the Hellenistic age is the diffusion of Hellenic culture—the “Hellenizing” of the Orient. It was, indeed, a changed world in which men were now living.
Greek cities, founded by Alexander and his successors, stretched from the Nile to the Indus, dotted the shores of the Black Sea and Caspian, and arose amid the wilds of central Asia. The Greek language, once the tongue of a petty people, grew to be a universal language of culture, spoken even by “barbarian” lips. And the art, the science, the literature, the principles of politics and philosophy, developed in isolation by the Greek mind, henceforth became the heritage of many nations.
In the period after Alexander the long struggle between East and West reached a peaceful conclusion. The distinction between Greek and Barbarian gradually faded away, and the ancient world became ever more unified in sympathies and aspirations. It was this mingled civilization of Orient and Occident with which the Romans were now to come in contact, as they pushed their conquering arms beyond Italy into the eastern Mediterranean.
From The Making of Europe / Early European History