Where does “hwu” come from?

hwu (Middle English) comes from Old English hū, from Proto-Germanic hwō, from Proto-Indo-European *kʷís.

Ancestry of “hwu”, step by step

StepLanguageWordMeaning
1Old Englishhūhow
2Proto-Germanichwōhow, with what, by what means; instrumental of...
3Proto-Indo-European*kʷís—
Every word from Proto-Indo-European *kʷís →Every word from Proto-Germanic hwō →Every word from Old English hū →