What do you mean by pre-history?

Answer 1

It seems a contradiction in terms, doesn't it? If it is prehistory, how do we know it? Generally, history refers to people and events that we can trace reasonably well in existing documentation of one kind or another. As we go farther back in time there is less and less reliable documentation. Prior to roughly the 3rd or 4th millennium BCE, there is no documentation that we would consider historically reliable. We have to infer the movements of populations and the levels of technology and sophistication from archeological data and the techniques used to interpret it.