What is nomadic era?
Nomadic empires, sometimes also called steppe empires, Central or Inner Asian empires, were the empires erected by the bow-wielding, horse-riding, nomadic people in the Eurasian Steppe, from classical antiquity (Scythia) to the early modern era (Dzungars). They are the most prominent example of non-sedentary polities.
When did nomads start?
Before around 1500 CE in the first areas of civilization (in modern day Iran, Iraq, Egypt, and Turkey), there were basically two ways of life: nomadic and settled. Nomads moved around to find resources, while settled farmers stayed in one place to form a community, eventually leading to the birth of cities.