ges in the city, then gradually repopulated by the inhabitants from its hinterland. However, during six decades of Gothic rule, the Goths saved those old Roman Municipal institutions that were still in function, while religious life in Dalmatia even intensified in the last years, so that there was a need for the foundation of additional bishoprics.
In 536 the Byzantine emperor Justinian the Great started a military campaign to reconquer the territories of the former Western Empire (see Gothic War); and in 553 Zadar passed to the Byzantine Empire. In 568 Dalmatia was devastated by an Avar invasion; although further waves of attacks by Avar and Slav tribes kept up the pressure, it was the only city which survived due to its protective belt of inland plains. The Dalmatian capital Salona was captured and destroyed in the 40s of the 7th century, so Zadar became the new seat of the Byzantine archonty of Dalmatia, territorially reduced to a few coastal cities with their agers and municipal lands at the coast and the islands nearby. The prior of Zadar had jurisdiction over all Byzantine Dalmatia, so Zadar enjoyed metropolitan status at the eastern Adriatic coast. At this time rebuilding began to take place in the city.At the beginning of the 9th century the Zadar bishop Donatus and the city duke Paul mediated in the dispute between the Holy Roman empire under Pepin and the Byzantine Empire. The Franks held Zadar for a short time, but the city was returned to Byzantium by a decision of the 812 Treaty of Aachen.
Zadar's economy revolved around sea, fishing and sea trade in the first centuries of the Middle Ages. Thanks to saved Antique ager, adjusted municipal structure and a new strategic position, it became the most important city between the Kvarner islands and Ka�tela Bay. Byzantine Dalmatia wasn't territorially unified, but an alliance of city municipalities headed by Zadar, and the large degree of city autonomy allowed the development of Dalmatian cities
