It is worth emphasizing that "Indo-European" is a linguistic description, not a genetic one. The Indo-European languages spread through Europe, Central Asia and the Indian Subcontinent largely through the people already living there shifting from the language they had been speaking before to Indo-European, because Indo-European had higher social prestige. That Iranians today speak an Indo-European language does not mean that their ancestors all came down from the steppe.
(In the last decades, work on historical DNA has identified certain genes that do appear to testify to some Indo-European population movements, but the impact of this is less than one might think for a discussion like this one.)
Here's an interesting (USA) article that illustrates this issue: https://www.latimes.com/projects/la-me-census-middle-east-no...
Are people from Teheran, for example, "white, black, Asian, American Indian, or Native Hawaiian" (copy-pasted the choices from the article)? In my opinion, American obsession with race is silly.
I think you've hit upon something here with defining "white". If "white" is something that you can freely define to suit your purpose, then there's no point in having this discussion. If we define "white" to be something more specific, that would make it easier to pin down some facts.
The bigger point is simply that Rome was ethnically diverse. After all, it was a huge empire, how could it not be?
Yes, they were ethnically diverse. That does not mean that Roman senators were any other than a bunch of white male people, and that the majority of its citizens weren't what anyone from Europe today would consider "white" or "caucasian". Of course, lots of people with even totally dark skin lived in Rome and other regions, but not to the extent of "Roman senators have to be depicted as black".
But now that you mention it, Septimius Severus was a dark-skinned Roman imperator: https://en.wikipedia.org/wiki/Severan_Tondo
The whole point is that ancient peoples, and especially Romans, are not a homogeneous group of people. Whether they define themselves as white is not what you should be arguing about, because most definitions of "white people" includes a diverse set of ethnicities as well.
WRT the Lybian Roman emperor: no one claims that ALL Roman citizen were white, or Italic, or European. Any such large Empire was heterogenous. But it is safe to say that a typical Roman citizen, espicially a Senator, would have been white for any reasonable definition of "whiteness", especially in a TV series. There was one black US president (his mother was white and father black if I remember correctly), but a typical US president so far was white.
I don't have anything against hiring a bunch of Chinese or Zimbabwean actors to play Senators, but that would certainly look odd. In the same way as hiring a bunch of Ukrainians to play Zulu warriors would look odd.
You also seem to be really caught up on senators. If you read the entire article, you'll note very little attention was given to senators.
Even so, that is not what the original argument was. The argument was that Rome was not homogeneous. Even in a heterogeneous society, there will be trends towards looking one way or another. The problem is simply with depicting all of Rome as (essentially) British.
Nobody has mentioned China or Zimbabwe, so this last argument is a lazy straw man.
We're circling back to the definition of "white". How's that a bold statement? Today's Great Britain has very diverse population, too, including lots of people from Africa, and yet I wouldn't think that a statement that a typical Brit is white is controversial. Typical Brit is not black, although there are many black British people, of course. And even if we constrain discussion to the most narrow definition of "white" (say, 18th century Englishmen) let's not forget that English people are the result of centuries of mixing of Britons, Germans, Celts... So, white Britons are themselves of diverse ancestry, but all these diverse ancestral people are "white". Let me repeat that race is an artificial construct, but if I'm pressed to say if someone is "white" or "not quite white" I can only go by outside appearance. Someone in Europe can have some genes from one Zimbabwean ancestor, but if he "looks white" to me, I can only say he's "white".
> The problem is simply with depicting all of Rome as (essentially) British.
Yes. That is a TV series. The point of TV series (in my opinion) is not to be 100% accurate, it's to entertain and (somewhat) educate. And the people in TV series are not real ancient Romans, but current actors. The series is for British audience, so it's normal that it's filled with British actors. If the series was produced in Bulgaria, the senators would be played by Bulgarian actors. Both are not exactly of the same color spectrum as ancient Romans, but are close enough to pass as Romans to their viewers. If the series was produced in China, and Romans were played by Chinese actors, that would probably pass as normal to Chinese audience. Maybe Zimbabwean actors could pass as Romans, at least in sub-Saharan Africa; why not? I'm not sure why people insist so much that British actors are bad representation of Romans. They seem quite OK to me (I'm not British).