You're right about the wee lad in The White Queen: he has finer features (not such a jutting chin) and is darker in colouring, but is definitely the best screen Richard. Age-wise, too, he was better than most, as he was playing him from teens to his death. Usually he gets played by people old enough to be his father. (A pity the production sucked as much as the books...)

Actually, looking at the thick dark hair and the eyes and cheekbones, I think young Aneurin would make a good Julian (thinking of the Musée de Cluny statue likeness). Wonder if he suits a beard?

Re: Heinrich IV: Yeah, he sounds like a stunner. The Pope and Matilda must've enjoyed getting an eyeful of that in his undies... And his great-grandsons were the Montferrat boys, who were also not lacking in the eye-candy department.