Acheulean

Assuming that language ability extends back to the hominids, we see a slow process of cultural development over millions of years, and then in the Acheulean period of Homo erectus, about three hundred thousand years ago, we find the first engraved tool.

When early modern humans – the ones who would eventually become us – started to move out of Africa something over a hundred thousand years ago, Acheulean tools were the technology of choice.