Where does “Luxemburger” come from?

Luxemburger (Dutch) comes from Dutch er, from Old Dutch iro.

Ancestry of “Luxemburger”, step by step

Step	Language	Word	Meaning
1	Dutch	er	there; him, her, it, them; of them, of those
2	Old Dutch	iro	—

Luxemburger — Etymology, Origin & Word History | Etymology Explorer