Meanwhile, the Croatian kings exacted tribute from the Byzantine cities, Tragurium, Iadera and others, and consolidated their own power in the purely Croatian-settled towns such as Nin, Biograd and Šibenik. The city of Šibenik was founded by Croatian kings. They also ascertained control over the bordering southern duchies. Rulers of the medieval Croatian state who had control over the Dalmatian littoral and the cities were the dukes Trpimir, Domagoj, Branimir, and the kings Tomislav, Trpimir II, Krešimir I, Stjepan Držislav, Petar Krešimir IV and Dmitar Zvonimir.