Where does “populaire” come from?

populaire (Old French) comes from Latin populāris, from Latin -āris, from Latin -ālis, from Proto-Italic -ālis.

Ancestry of “populaire”, step by step

Step	Language	Word	Meaning
1	Latin	populāris	—
2	Latin	-āris	—
3	Latin	-ālis	—
4	Proto-Italic	-ālis	—