Except that the Henry V in question was a German guy. :) "The Holy Roman Empire", despite its name, was initially a Frankish and then a purely German institution, comprising a lot of the lands of Central Europe (plus a bit of Western Europe, for as while).
Ah yes, I see your point now. A couple of centuries after the first Henry V, there’s another Henry V, born in England.
Of course, there are plenty of kings and child brides to choose from. How about Richard II of England, who married Isabella of Valois when she was 6 years old?
http://en.wikipedia.org/wiki/Matilda_of_England