built for them . During Late Antiquity (late Roman/early Byzantine period), the island formed part of the province of Epirus Vetus in the praetorian prefecture of Illyricum. In 551, during the Gothic War, the Ostrogoths raided the island and destroyed the city of Corfu, then known as Chersoupolis (Χερσούπολις, "city on the promontory") because of its location between Garitsa Bay and Kanoni. Over the next centuries, the main settlement was moved north, to the location of the current Old Fortress, where the rocky hills offered natural protection against raids. From the twin peaks of the new site, the medieval city received its new name, Korypho (Κορυφώ, "city on the peak") or Korphoi (Κορφοί, "peaks"), whence the modern Western name of "Corfu". The previous site of the city, now known as Palaiopolis (Παλαιόπολις, "old city"), continued to be inhabited for several centuries, however. From at least the early 9th century, Corfu and the other Ionian Islands formed part of the theme of Cephallenia. This naval theme provided a defensive bulwark for Byzantium against western threats, but also played a major role in securing the sealanes to the Byzantine possessions in southern Italy. Indeed, traveller reports from throughout the middle Byzantine period (8th–12th centuries) make clear that Corfu was "an important staging post for travels between East and West". Indeed, the medieval name of Corfu first appears (Latinized Coryphus) in Liutprand of Cremona's account of his 968 embassy to the Byzantine court. Corfu enjoyed relative peace and safety during the Macedonian dynasty (867–1054), which allowed the construction of a monumental church to Saints Iason and Sosipatrus outside the city wall of Palaiopolis. Nevertheless, in 933, the city, led by its archbishop, Arsenios, withstood a Saracen attack; Arsenios was canonized and became the city's patron saint. The peace and prosperity of the Macedonian era ended with another Saracen attack in 1033, but more importantly with the emergence of a new threat: following the Norman conquest of Southern Italy, the ambitious Norman monarchs set their sights on expansion in the East. Three times on the space of a century Corfu was the first target and served as a staging area for the Norman invasions of Byzantium. The first Norman occupation from 1081 to 1084 was ended only after the Byzantine emperor Alexios I Komnenos secured the aid of the Republic of Venice, in exchange to wide-ranging commercial concessions to Venetian merchants. The admiral George