“They were depicted by Roman sources as ungovernable nomadic barbarians.”
Well, it’s pretty obvious that the Garamantes could by governed by themselves. It’s the *Romans* that they weren’t interested in being governed by.
Of course, the Romans wrote the history books after the Garamantes were gone, so they could depict them in any way they wanted. That’s usually the way it works: empires always depict the people that fight back as “barbarians,” “uncivilized,” “pagans,” “primitive.” That why I love Herodotus. He reports these civilizations as an anthropologist would, without judgment. It makes for much more informative reading.
Yup, Herodotus had no axes to grind, unlike his ancient-world critics and the mob of misinformed and/or Muzzies out there. He traveled in Egypt as well as in the Persian empire, and preserved an invaluable corpus of testimony that would otherwise have been lost. The example I usually cite is his discussion of why the Nile floods out of season. He lists three that he heard, including the real reason, which he notes is the least likely of all, then offers a fourth of his own that’s unintentionally hilarious. :’) That’s a good example of his honesty, something often lacking in historians then and now.