Where does “treve” come from?

treve (Old French) comes from Proto-West Germanic treuwu, from Proto-Germanic trewwō, from Proto-Indo-European drewo-.

Ancestry of “treve”, step by step

StepLanguageWordMeaning
1Proto-West Germanictreuwufidelity, pledge
2Proto-Germanictrewwōfidelity, pledge
3Proto-Indo-Europeandrewo-—
Every word from Proto-Indo-European drewo- →Every word from Proto-Germanic trewwō →Every word from Proto-West Germanic treuwu →