Louis is the French form of
Ludwig, the modern
German form of the Germanic name Hludwig.
Lewis is technically the English version, though
Louis was quickly taken up by English speakers and is now an English form in its own right (via its different pronunciation from the original French).
Clovis is the Latinised form of Hludwig and was used by
King Clovis of the Franks, who united
France in the 6th century and thereby started the fashion of French kings being named
Louis: 17, not including Louis-Philippe or
Louis Napoleon Bonaparte.
I prefer
Louis in general, as
Lewis seems surnamey to me. Also,
Louis looks prettier to me, for lack of a better word.
Miranda