[hga]

Per Wikipedia, this concept only goes back to the early '60s, which matches my general reading on this sort of thing in the '70s as I struggled to understand what had just happened in the Vietnam War (I came of political age just as it was ending): https://en.wikipedia.org/wiki/Leaderless_resistance#History

[wavefunction]

The early revolution certainly saw the emergence of guerilla warfare if not earlier instances providing that same starting-point. War was a formal issue for many clashes throughout the ages: generally an amassing of resources, a relative comparison and victory to the amasser of "more" with some casualties paid as an afterthought. But guerilla warfare presuposes that a more numerous and detested occupier cannot win because they are faced with a choice of extinguishing their enemies (the domestic population conquered) or being driven from those same holdings.