Where does “বাঙ্গালা” come from?

বাঙ্গালা (Middle Bengali) comes from Sanskrit वङ्गाल.

Ancestry of “বাঙ্গালা”, step by step

Step	Language	Word	Meaning
1	Sanskrit	वङ्गाल	—

বাঙ্গালা — Etymology, Origin & Word History | Etymology Explorer