Where does “Tsjechië” come from?

Tsjechië (Dutch) comes from Dutch ie, from Middle Dutch hi, from Old Dutch hīe, from Old Dutch hē, from Proto-Germanic *hiʀ, from Proto-Germanic hīz — nominative plural masculine of *hiz; these, these...

Ancestry of “Tsjechië”, step by step

Tsjechië traces back through two separate lines of ancestry.

via Dutch ie

Step	Language	Word	Meaning
1	Dutch	ie	"Third-person singular, masculine, subjective,...
2	Middle Dutch	hi	he
3	Old Dutch	hīe	he
4	Old Dutch	hē	—
5	Proto-Germanic	*hiʀ	—
6	Proto-Germanic	hīz	nominative plural masculine of *hiz; these, these...

via Dutch Tsjech

Step	Language	Word	Meaning
1	Dutch	Tsjech	Czech (person)
2	Czech	čech	—
3	Old Czech	Čech	Czech person
4	Proto-Slavic	čelověkъ	man, human
5	Proto-Indo-European	(s)kʷel-	crowd, people
6	Proto-Indo-European	kʷel-	to turn

Every word from Proto-Germanic hīz →Every word from Proto-Germanic *hiʀ →Every word from Old Dutch hē →