I am inclined to think that this argument—that "Ethiopians" in antiquity inhabited the Sahara & North Africa—isn't really supported by the ancient evidence. Long thread below to explain why. https://twitter.com/kataplexis/status/1316761635441135627

Here's (briefly) what Herodotus says about the location of the Aethiopes:
1. Ethiopians dwell 4 days’ sail up the Nile from Aswan. Their metropolis is Meroe (2.29).
2. The "long-lived Aethiopes" live south of Egypt. They dwell in Libya "beside the southern sea." (3.17)

(Notes on terminology: "Libya" here is being used as the ancient name for the continent Africa. The "southern sea" is arguably the "Erythraean Sea," i.e. the Indian Ocean, or it is the sea that was thought to bound Libya/Africa to the south....

...and there is some uncertainty about whether "macrobioi" is just an attribute of Aethiopes generally or whether the "macrobioi Aethiopes" are a subgroup.)

Anyway:
3. The Aethiopes dwell in the most southwest extreme of the inhabited earth. (3.114) (Not clear here if these are the same as the Aethiopes who live south of Egypt; possibly also Herodotus is trying to "save" the Homeric version of the Aethiopes here.)

4. The Aethiopes are native to the continent of Libya (Africa) and they dwell in the southern part of it (4.197).

Further, in the latter chapters of Book 4 (4.168–199), Herodotus gives a survey of all the Libyan inhabitants of North Africa: those who live along the coast, and those who inhabit the ridge of sand extending "from Egyptian Thebes to the Pillars of Hercules." (4.181)

At no point in this section (unless I have forgotten something) does he mention any groups of Aethiopes. And at 4.185 he states that, beyond this ridge the parts to the south and the interior of Libya are uninhabited desert.

In sum: Libyans live along the N. African coast and in the northern parts of the Sahara. South of the Libyans is uninhabited desert. Ethiopians live (1) south of Egypt, (2) in the southern part of the continent by the southern sea, and (3) at the southwest extreme of the world.

To conclude that Hdt. says Ethiopians live north of the Sahara, you must assume that all those references to the "southern part" of the continent and "the southern sea" somehow still refer to North Africa, which seems to me to be very hard to support from the text.

(I am setting aside the Aethiopes of India, since this is not the point of disagreement here and this thread is already far too long.)

The blog post linked in the thread above says: “And according to Herodotus, they are living north of the Sahara, since the Sahara beyond its edges merges into the uninhabitable zone and then Ocean.”

But the former claim (north of Sahara) seems pretty clearly contradicted by the evidence laid out here. And the latter claim (habitation south of Sahara is impossible because it merges into Ocean) does not seem to be a view Herodotus holds (though some ancient geographers do).

For one, Herodotus doesn't believe that the river Ocean as traditionally understood exists (2.33).

Further, at 2.32–33 he tells the tale of the Nasamonians who travel south and west from the Mediterranean coast across the interior desert of Libya and eventually find inhabitants (who, incidentally, have black skin but whom H. does not ID as Aethiopes).

So it seems he does think habitation south of the Sahara is possible (as it ought to be if he truly believes the Nile runs west to east below the desert before flowing down through Egypt, as he suggests).

Herodotus could be wrong about all this, of course! And some of the evidence he presents is more than a little opaque. But my point is simply that, if this is a problem, it is a problem that is already there in the text of Herodotus. It is not simply an “us problem.”

OK, to wrap up, two important qualifications to all of the above—and points on which (despite my rather vehement disagreement here) I think Dr. Kennedy and I might agree.

1. As already seen in the story of the Nasamonian travelers, not all black people in antiquity were Ethiopians. The North African peoples listed in Book 4 are not Ethiopian—but some of them still very well may have been black. (Hdt. does not really mention their skin color.)

So my argument has nothing whatsoever to do with the possibility of black inhabitants of North Africa in the ancient world. I am just questioning the localization and meaning of the specific term Aethiopes.

2. The "sub-Saharan" vs. "North African" racial-cultural divide is one which seems to loom much larger in the mind of moderns (surely due to our own racial constructs) than it did for the ancients.