Where does “*illūrum” come from?

*illūrum (Vulgar Latin) comes from Latin illōrum, from Proto-Indo-European h₂él-.

Ancestry of “*illūrum”, step by step

Step	Language	Word	Meaning
1	Latin	illōrum	—
2	Proto-Indo-European	h₂él-	—

*illūrum — Etymology, Origin & Word History | Etymology Explorer