Alexander the Great had a unique way of conquering those around him that did not involve the treating of captives as caged animals, such as was commonly done by surrounding empires, such as the Ninevites. His was a way he learned from his teacher Aristotle.
Aristotle taught, to use my own summation:
Change the language, and you conquer the people.
In other words, when Alexander invaded a foreign area, he would employ what we today call 'assimilation' (in this case, 'hellenization'). It involved getting the foreign people to adopt the language of the Greek people, which then would spread into the adopting of their culture.
While that is something that happened long ago, the principle Aristotle gave Alexander still holds true to this day, especially in the religious world. The difference however, is that rather than necessarily referring to a different language, per se (Greek, Hebrew, Latin, English, Spanish...etc), I am referring to the assimilation of a different way of defining words of a given language. It is just as effective in creating assimilation and change as the learning of the language of a people group.