Slavs surely did not occupy the whole interior or eliminate the Greek population since some Greek villages continued to exist in the interior, probably governed themselves and possibly paid tribute to the Slavs. Some villages were probably mixed, and quite possibly, some degree of Hellenization of the Slavs by the Greeks of the Peloponnese had already begun during this period, before re-Hellenization was completed by the Byzantine emperors. When the Byzantines were not fighting in their eastern territories, they slowly regained imperial control. That was achieved through its theme system, which refers to an administrative province on which an army corps was centred under the control of a strategos ("general"). The theme system first appeared in the early 7th century, during the reign of the Emperor Heraclius. As the Byzantine Empire recovered, the system was imposed on all areas that came under Byzantine control. The first Balkan theme was created in Thrace in 680 AD. By 695, a second theme, that of "Hellas" (or "Helladikoi"), was established, probably in eastern central Greece. Subduing the Slavs in the themes was simply a matter of accommodating the needs of the Slavic elites and providing them with incentives for their inclusion into the imperial administration. It was not until 100 years later that a third theme would be established. In 782–784, the eunuch general Staurakios campaigned from Thessaloniki, south to Thessaly and into the Peloponnese. He captured many Slavs and transferred them elsewhere, mostly Anatolia (these Slavs were dubbed Slavesians). However, it is not known whether any territory was restored to imperial authority as result of the campaign although it is likely that some was. Sometime between 790 and 802, the theme of Macedonia was created, centred on Adrianople (east of the modern geographic entity). A serious and successful recovery began under Nicephorus I (802–811). In 805, the theme of the Peloponnese was created. According to the Chronicle of Monemvasia the Byzantine governor of Corinth went in 805 to war with the Slavs, obliterated them and allowed the original inhabitants to claim their own. The city of Patras was recovered and the region resettled with Greeks. In the 9th century, new themes continued to arise although many were small and were carved out of original larger themes. New themes in the 9th century included those of Thessalonica, Dyrrhachium, Strymon and Nicopolis. From those themes, Byzantine laws and culture flowed into the interior. By