'Louis' originates from Old Frankish/Germanic, specifically the name 'Hludwig' (via Latin 'Ludovicus'), where 'hlūd' meant 'fame' and 'wīg' meant 'warrior' or 'battle'.

'Louis' changed from the Germanic name 'Hludwig' to Latin 'Ludovicus', then to Old French forms such as 'Looïs'/'Loui(s)', and eventually became the modern French and English name 'Louis'.

Initially it meant 'famous in battle' (a descriptive compound meaning), but over time it became used primarily as a personal name without carrying that literal descriptive sense for most speakers.