Three Victorians:

John Stuart Mill,

Frank Lloyd Wright

and

James McNeill Whistler,

have in common first names that cannot be used without a second.  You can’t simply say “John Mill” or “Frank Wright” or “James Whistler” *.  But these aren’t hyphenated Roman Catholic names (John-Paul, for example) and they aren’t double-barreled last names.  Wright — a very vain man (you see it in the photograph: look at the side-lighting and the necktie) — was always known (perhaps even to his parents) as “Mr Wright”;  I’ve certainly never heard of anyone who addressed him as… “Frank”.

There are some others where the reason for the extra name is clear:  Charles James Fox (a little earlier) was presumably named after the Stuart king from whom he was illegitimately descended.  Isambard Kingdom Brunel’s name was always begging to be recited in full.  Charles Lutwidge Dodgson’s first names are linguistically related to his pen-name, Lewis Caroll.

I expect there are loads more — Henry Wadsworth Longfellow, isn’t he one?  Am I right that this is mostly a 19th century thing, and can anyone supply a convincing reason why it’s done?  Why not “John Mill”, why is the “Stuart” necessary? Did his wife call him John Stuart?   Reciting the extra name is, after all, an enormous waste of energy and time.

* (I don’t include George Bernard Shaw on the list, because he is also known — at least in Britain — as Bernard Shaw).