After the fall of the Western Roman Empire, the Ostrogoths occupied Genoa. After the Gothic War, the Byzantines made it the seat of their vicar. When the Lombards invaded Italy in 568, Bishop Honoratus of Milan fled and held his seat in Genoa. Pope Gregory the Great was closely connected to these bishops in exile, for example involving himself in the election of Deusdedit. The Lombards, under King Rothari, finally captured Genoa and other Ligurian cities in about 643. In 725 the mortal remains of Augustine of Hippo arrived in Genoa. In 773 the Lombard Kingdom was annexed by the Frankish Empire; the first Carolingian count of Genoa was Ademarus, who was given the title "praefectus civitatis Genuensis". Ademarus died in Corsica while fighting against the Saracens. In this period the Roman walls, destroyed by the Lombards, were rebuilt and extended.