Domestic horses promoted rapid and long-distance human mobility from ~2,200 BCE

Horses revolutionized human history with fast mobility. However, the timeline between their domestication and widespread integration as a means of transportation remains contentious. Here, we assemble the largest collection of ancient horse genomes to assess the period when these animals were first reshaped by human agency in Eurasia. We find that reproductive control of the modern domestic lineage emerged ~2,200 BCE, through close kin mating and shortened generation times. It followed a severe domestication bottleneck starting not earlier than ~2,700 BCE, and coincided with a sudden expansion across Eurasia that ultimately replaced nearly every local horse lineage. This expansion marked the rise of widespread horse-based mobility in human history, which refutes the commonly-held narrative of large horse herds accompanying the massive migration of steppe peoples into Europe ~3,000 BCE and earlier. We detect significantly shortened generation times at Botai ~3,500 BCE, a settlement from Central Asia associated with corrals and a subsistence economy centered on horses. This supports local horse husbandry before the rise of modern domestic bloodlines.