Where does “Argolis” come from?

Argolis (English) comes from Ancient Greek Ἀργολίς, from Ancient Greek Ἄργος — Argos.

Ancestry of “Argolis”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Ἀργολίς	—
2	Ancient Greek	Ἄργος	Argos

Argolis — Etymology, Origin & Word History | Etymology Explorer