THE SLAVS
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Sulona, destroyed in 639. The prosperous period of Roman Dalmatia was closed.
| The Imperial topographer Constantine VII. Porphyrogennetos, our chief authority on early Dalmatia, writing between 948 and 952, clearly distinguishes between the Dalmatian mainland plateau (ra v-fyrfkoTepa p-ept]) and the seaboard towns (to Trjs TrapaXias Kaarpa). What really remained after the Avar invasion and devastation was the Slav-Croat population which occupied the mainland and some of the islands of Dalmatia, and throughout all the vicissitudes of Hungarian, Venetian and Turkish rule continued to be the true mainland population down to the present day, with the seats of their rulers or ¿upans at Nona, Bihad, Bribir, Biograd and Vrana, where ruins of their forts and castles are still visible. But seeing that the coast-line, its cities and harbours and outlying islands were the things of chief importance in Dalmatia, it is the fluctuating possession of these rather than supremacy on the mainland that constitutes the central interest of Dalmatian history.
  Dalmatia was still the Thema Dcilmata in the Byzantine Empire when Charlemagne endeavoured to conquer the lagoon-state of Venice in order to create for himself sea-power for the purpose of