Where does “Maximilien” come from?

Maximilien (French) comes from Latin Maximilianus, from Latin Maximus, from Proto-Italic *magisVmos.

Ancestry of “Maximilien”, step by step

StepLanguageWordMeaning
1LatinMaximilianus—
2LatinMaximusthe greatest
3Proto-Italic*magisVmos—
Every word from Proto-Italic *magisVmos →Every word from Latin Maximus →Every word from Latin Maximilianus →