[TOMT] [person] Recently deceased historian (maybe?)

I'm pretty this person died this year. White male historian, died in old age, reputed to have a great memory, wrote extensively, someone said he was one of the best historians of modern times. I saw him on the Wikipedia front page (? this may be wrong, since I've checked all over the archives for this guy). Wikipedia article has photo of him, black and white.

Either English or American.

Thanks guys!