Louis

If the name Louis is related to the name Lewis, it is also related to Lugas (French), Lugh (Irish) and Llew (Welsh). There is no greater hero warrior in pre-Roman times than Lugh.
Lugh means 'The Shining One'. He is the new sun of the year born at the equinox in mid winter. He grows in strength until he can destroy Balor 'The Shadowy One' or the winter sun.
He later marries the Earth each year and becomes King of Tara, "Lugh of the Long Arm' the King of the Fairies ie., the summer sun.
Analogous to Apollo/Zeus, Odin/Woden...

Louis may also be a derivative of the Germanic name Clovis.