The town's name probably came from the ancient Roman city Hadrianopolis, which was located near present day Deriana.
It is thus that the see appears in the sources from the 9th century on as "Nafpaktos of Nicopolis" (μητρόπολις Ναυπάκτου Νικοπόλεως), counting initially eight suffragans covering all of Epirus: Vonditsa, Aetos, Acheloos, Rogoi, Ioannina, Photiki, Hadrianopolis, Buthrotum.