In 1147, Roger attacked the Byzantine Empire, which continued to contest his gains in southern Italy. George he sent from Otranto with seventy galleys to assault Corfu. According to Nicetas Choniates, the island capitulated due to the imperial tax burden and George's promises. Leaving a garrison, George sailed on to the Peloponnesus. He sacked Athens and quickly moved on to the Ionian Islands. He ravaged the coast all along Euboea and the Gulf of Corinth and penetrated as far as Thebes, where he pillaged the silk factories and carried off the Jewish silk weavers. George capped the expedition with a sack of Corinth, in which the relics of Saint Theodore were stolen, and then returned to Sicily.