Indo-European migrations

The Indo-European language and culture spread in several stages from the Proto-Indo-European Eurasian homeland at the Pontic steppes, into western Europe, central Asia and India. This process started with the introduction of cattle at the Eurasian steppes around 5200 BCE, which led to a new kind of culture. Between 4500 and 2500 this "horizon", which includes several distinctive cultures, spread-out over the Pontic steppes, beginning ca. 4000 BCE. At ca. 2000 BCE Indo-European languages started to appear outside the Eurasian steppes.
Origins
Proto-Indo-Europeans
The Proto-Indo-Europeans were the speakers of the Proto-Indo-European language (PIE), a reconstructed prehistoric language of Eurasia.
Knowledge of them comes chiefly from the linguistic reconstruction, along with material evidence from archaeology and archaeogenetics. According to some archaeologists, PIE speakers cannot be assumed to have been a single, identifiable people or...