[2][4] The exact boundaries of the Theme of Nicopolis are not known in detail, but probably matched the extent of the Metropolis of Naupaktos, established at about the same time, and which encompassed the suffragan sees of Vonditsa, Aetos, Acheloos, Rogoi, Ioannina, Hadrianopolis, Photike, and Buthrotum.

[6] Basil II also founded a few smaller themes, comprising little more than a fortress and its immediate surroundings, those of Koloneia and Dryinoupolis, in what is today the Greco-Albanian border region.

[6] In 1040, following the murder of a corrupt and oppressive taxation official – according to John Skylitzes, the locals were notorious for being ready to revolt for fiscal reasons[7] – most of the theme joined the uprising of Petar Delyan.

A chrysobull of 1198 mentions it along with the themes of Dyrrhachium and Ioannina, and records that it was further subdivided into smaller fiscal districts (episkepseis) belonging to churches, monasteries and individuals.

The Greek noble Michael Komnenos Doukas, who had married the daughter of the governor of Nicopolis, took advantage of this, and within a few years consolidated his control, first as a Venetian vassal and eventually as an independent ruler.

In addition, as the theme was a major base for Byzantine operations across the Adriatic into southern Italy, and hosted a contingent of Mardaites marines, probably under their own katepano.