Under the Byzantine Empire, the city rose to relative prominence. It is mentioned as the site of the destruction of an Arab fleet by storm in late 677 or 678, following the unsuccessful Arab Siege of Constantinople. As one of the major fortified sites of the area, it became the seat of an imperial representative ("ek prosōpou"), complementing the "stratēgos" of the naval theme of the "Kibyrrhaiotai". Syllaeum was also located at the start of the great public road that linked the southern coast, via Amorium and Nicaea, with Bithynia and the capital Constantinople. In this position, it began to eclipse the traditional local metropolis of Perge, and sometime between 787 and 815, the local bishop's seat was transferred to Syllaeum. Together with the wider area of Pamphylia, the city fell to the Seljuks in 1207.