It's certainly novel. It's strange to pick 193 as the collapse of the Roman Empire, because that's the year Septimius Severus became emperor, and he was north African. The British Museum has this to say about his ethnicity:

Although his family was of Phoenician rather than black African descent, ancient literary sources refer to the dark colour of his skin and relate that he kept his African accent into old age.

It's also strange to mention the Tudors as among the rulers that have been "whitewashed" if 1453 is the date for that. Henry wasn't born for almost another 40 years and didn't become king until 1509. Seems strange that original portraits of Henry would represent him as black if there is a European conspiracy in operation for more than 50 years now to whitewash history. England wasn't exactly an intellectual backwater at this point.

This theory would also require rewriting the classical literary tradition, which I suppose these guys wouldn't have a problem with. The comparatively dark color of the skin of people in the south has been commented on since Homer:

Zeus went yesterday to Oceanus, to the blameless Ethiopians for a feast

"Αἰθίοψ" defined in the LSJ is this:

A. [select] “Αἰθιοπῆες” Il.1.423, whence nom. “Αἰθιοπεύς” Call.Del.208: (αἴθω, ὄψ):—properly, Burnt-face, i.e. Ethiopian, negro, Hom., etc.; prov., Αἰθίοπα σμήχειν 'to wash a blackamoor white', Luc.Ind. 28.

although I suppose you could argue the dictionary has been whitewashed as well. A passage from the Aethiopica is a little harder to deal with - this is a 4th century CE novel in which skin color, specifically the birth of a white skinned girl to a black couple - is central to the plot:

In that chamber, after Hydaspes had been married to me ten years and we had never a child, we happened to be resting one summer day, for that we were drowsy with the fierce heat. And it was then that your father had to do with me, swearing that by a dream he was commanded so to do; and I by and by perceived myself to be with child. All the time after until I was delivered was kept as a public festival and sacrifices of thanksgiving were offered to the gods, for that the king hoped now to have one to succeed him in his kingdom. But thou wert born white, which colour is strange among the Ethiopians. I knew the reason, that it was because, while my husband had to do with me, I was looking at the picture of Andromeda brought down by Perseus naked from the rock, and so by mishap engendered presently a thing like to her. But counting it certain that thy colour would procure me to be accused of adultery, and that none would believe me when I told them the cause, I determined to rid myself of shameful death and to commit thee to the unstableness of fortune....

There is a theory published in Bernal 's 1981 book Black Athena that makes the case that Greek culture derives from African civilizations rather than European ones. It's a strange book. It attacks some of the basic assumptions of the study of the Classical world and upset a lot of people. Other people, while ultimate rejecting the more extreme claims of the book, appreciate it as a necessary corrective to a discipline that had been founded in and perpetuated Eurocentrism. For example, here is a review criticizing one response to Black Athena. You'll see it doesn't address factual claims so much as ideologies that interpret those claims. At my university, depending on the professor, Black Athena will be mentioned in Greek Myth classes, and one result of this book is that we usually go out of our way to point out non-IE influences in Greek culture, though usually Asiatic, not African.

These guys have a point as far as traditionally the study of the ancient world focused on the Indo-European aspects of the culture and that is probably a mistake. An international Caucasian conspiracy to literally paint people of dark skin out of pictures, well....