Where does “quisque” come from?

quisque (Latin) comes from Latin quis, from Proto-Italic kʷis, from Proto-Indo-European *kʷís.

quisque (Latin): each one, each person; anyone

Definitions

Step	Language	Word	Meaning
1	Latin	quis	who, what; how, why; someone, something, anyone,...
2	Proto-Italic	kʷis	who, what
3	Proto-Indo-European	*kʷís	—

quisque — Etymology, Origin & Word History | Etymology Explorer