That would depend on how you define Guerrilla warfare. Technically, guerrilla warfare as we define it today may well have been the original form of warfare before the rise of organized nations large and centralized enough to engage in what we today would think of as conventional warfare. However, the term only really becomes relevant in contrast to conventional warfare so I guess the answer would be that it has always been around for as long as there have been asymetrical conflicts.

Instances of guerrilla warfare exist in almost every record of early warfare from Sun Tzu in China to tribes in Europe whether they were fighting Romans, Macedonians or Persians.