B[y]elorussia vs. White Russia 

Yes, , I agree that this is indeed a question of history rather than language per se, though the choice of version seems to hinge on matters of Cyrillic-to-English transliteration. My choice of the Language RD rather than Humanities was based on a rather pragmatic decision of where I'd be likely to get the more reputable, hence useful, answer. I hope that this mild though not-wholly-innocent manipulation on my part will be viewed with indulgent tolerance (and perhaps even sympathetic comprehension) by my fellow RD contributors, certainly in view of my regular serious efforts there!  Cheers,