The Athenians, who were now besieged by Macedonian forces, sent an appeal to the Roman force in Corcyra. Gaius Claudius Centho was sent with 20 ships and 1,000 men to aid them. Philokles and his troops withdrew from Attica to their base in Corinth. In response to a request from Chalcidean exiles, Claudius led a surprise raid on the city of Chalcis in Euboea, one of the key Antigonid strongholds known as the 'fetters of Greece' and inflicting serious damage and heavy casualties.