Louis (pronounced [lwi] in French, /ˈluːiː/ in British English or /ˈluːɪs/ in American English) is the French and English form of the German given name Ludwig.[1] Another English variant is Lewis (/ˈluːɪs/). The German name is composed of the words for "fame" (hlūd) and "warrior" (wīg) which may be translated to famous warrior or "famous in battle".[2]
http://en.wikipedia.org/wiki/Louis_(given_name)