the hypothesis deriving from this observation , which came to be so influential , was that the very widespread distribution of what came to be called the indo-european family of languages had been affected , in historic time , by the mass movement of a race of peoples ; the aryans , who , coming in migratory waves had left a homeland ( perhaps the caucasus mountain areabut never identified with certainty ) and divided en route with some going to what became europe , the rest to what became india .