Where does “Pampanga” come from?

Pampanga (Cebuano) comes from Spanish Pampanga, from Spanish -a, from Latin -a, from Proto-Italic -ā, from Proto-Indo-European -éh₂.

Ancestry of “Pampanga”, step by step

Step	Language	Word	Meaning
1	Spanish	Pampanga	—
2	Spanish	-a	-ess used to form feminine singular nouns; used...
3	Latin	-a	suffixed to the roots of verbs, forms agent...
4	Proto-Italic	-ā	Forms masculine agent nouns from prefixed or compounded bases
5	Proto-Indo-European	-éh₂	—