Herodotus (c.490-c.425 BCE):
On Libya, from The Histories, c. 430 BCE
These be the Libyan tribes whereof I am able to give the names; and most of these cared little then, and indeed care little now, for the king of the Medes. One thing more also I can add concerning this region, namely, that, so far as our knowledge reaches, four nations, and no more, inhabit it; and two of these nations are indigenous, while two are not. The two indigenous are the Libyans and Ethiopians, who dwell respectively in the north and the south of Libya.
The Libyans dwell in the order which I will now describe. Beginning on the side of Egypt, the first Libyans are the Adyrmachidae. These people have, in most points, the same customs as the Egyptians, but use the costume of the Libyans. Their women wear on each leg a ring made of bronze; they let their hair grow long, and when they catch any vermin on their persons, bite it and throw it away. In this they differ from all the other Libyans.
Westward of the river Triton and adjoining upon the Auseans, are other Libyans who till the ground, and live in houses: these people are named the Maxyans. They let the hair grow long on the right side of their heads, and shave it close on the left; they besmear their bodies with red paint; and they say that they are descended from the men of Troy.
For the eastern Ethiopians have straight hair, while they of Libya are more woolly-haired than any other people in the world.
Evidently Libya was the generic name for the known Africa during Herodotus’s time.
“Ethiopian” in this context would just mean “non-Greek” people who were not Persian or Assyrian or Babylonian. “Aethiops” does not seem to refer to “dark/sunburnt” persons since the Greek roots for “black coloured” would be “melanchros” from which is derived the terms “melanin”, “Melanesia” and “chros” gives is “cromosome” and “chromatic”, etc.
But the main point still stands: “Libya”, in Herodotus’s time, referred to all of the then known Africa. “Eastern Ethiopians” would then seem to refer to the people external to Africa in places now known as Pakistan and India[ recall that Alexander invaded places as far East as India]