World History

The terrain in Central Asia has always lent itself to the nomadic lifestyle.

Nomadism is better in vast grasslands. Since humans can't eat grass, these societies are dependent on animals. The animals convert the grass into meat, fur, milk, and transportation. There's also the issue of security. It's hard to construct defensible positions on the steppe, so it helps to be highly mobile. Plus animals have to move around throughout the year, since different grazing lands are needed during different times of the year.

Interesting stuff.