The earliest states were all created by steppe nomads, who had domesticated livestock (cows, sheep, horses, goats, etc) and realized that they could perpetually dominate the people who had domesticated plants. The nomads would bring their livestock everywhere with them, including in war. And they would ride their horses in combat, which the farmers had not yet gotten ahold of. It was the most un-even match in history, since the farmers had no idea what was going on, until it was too late.

Rcommended reading: https://en.wikipedia.org/wiki/Against_the_Grain:_A_Deep_History_of_the_Earliest_States