Where does “捷克” come from?

捷克 (Chinese Mandarin) comes from English Czech, from Polish Czech, from Czech čech, from Old Czech Čech, from Proto-Slavic čelověkъ, from Proto-Indo-European (s)kʷel-, from Proto-Indo-European kʷel- — to turn.

Ancestry of “捷克”, step by step

Step	Language	Word	Meaning
1	English	Czech	Of, from, or pertaining to the Czech Republic,...
2	Polish	Czech	Czech man; Bohemian man
3	Czech	čech	—
4	Old Czech	Čech	Czech person
5	Proto-Slavic	čelověkъ	man, human
6	Proto-Indo-European	(s)kʷel-	crowd, people
7	Proto-Indo-European	kʷel-	to turn

Every word from Proto-Indo-European kʷel- →