Where does “Ядвига” come from?

Ядвига (Russian) comes from Polish Jadwiga, from Old High German Haduwig, from Proto-Germanic Haþuwīgą, from Proto-Germanic haþuz, from Proto-Indo-European kéh₃tus, from Proto-Indo-European -tus — Derives action nouns from verb roots.

Ancestry of “Ядвига”, step by step

StepLanguageWordMeaning
1PolishJadwiga—
2Old High GermanHaduwig—
3Proto-GermanicHaþuwīgą—
4Proto-Germanichaþuzbattle, fight
5Proto-Indo-Europeankéh₃tusfight
6Proto-Indo-European-tusDerives action nouns from verb roots
Every word from Proto-Indo-European -tus →Every word from Proto-Indo-European kéh₃tus →Every word from Proto-Germanic haþuz →