According to the widely accepted
Kurgan hypothesis, 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 2000 BCE, this "horizon", which includes several distinctive cultures, spread-out over the Pontic steppes, and outside into Europe and Asia.