Fondi, Terracina and Ostia on the River Tiber, causing the church bells in Rome to sound the alarm. In Sperlonga he took 10,000 captives and when he arrived in Fondi the janissaries entered the city through the main gates and completely ransacked the palace of Giulia Gonzaga. He then sacked, torched and destroyed Vallecorsa slaughtering some townspeople and taking others captive. He sailed south, appearing at Ponza, Sicily and Sardinia, before capturing Tunis in August 1534 and sending the Hafsid Sultan Mulay Hassan fleeing. He also captured Tunis' strategic port of La Goulette the same year. Charles dispatched an agent to offer Barbarossa "the lordship of North Africa" for his changed loyalty, or if that failed, to assassinate him. However, upon rejecting the offer, Barbarossa decapitated the agent with a scimitar. Mulei Hassan asked Emperor Charles V for help in recovering his kingdom, and a Spanish-Italian force of 300 galleys and 24,000 soldiers recaptured Tunis as well as Bône and Mahdiya in 1535. Recognizing the futility of armed resistance, Barbarossa had abandoned Tunis well before the arrival of the invaders, sailing away into the Tyrrhenian Sea, where he bombarded ports, landed once again at Capri and reconstructed a fort (which still today carries his name) after largely destroying it during the siege of the island. He then sailed to Algiers, from where he raided the coastal towns of Spain, destroyed the ports of Majorca and Menorca, captured several Spanish and Genoese galleys and liberated their Muslim oar slaves. In September 1535, he repulsed another Spanish attack on Tlemcen. In 1536, Barbarossa was called back to Constantinople to take command of 200 ships in a naval attack on the Habsburg Kingdom of Naples. In July 1537, he landed at Otranto and captured the city, as well as the Fortress of Castro and the city of Ugento in Apulia. In August 1537, Lütfi Pasha and Barbarossa led a huge Ottoman force that captured the Aegean and Ionian islands belonging to the Republic of Venice, namely Syros, Aegina, Ios, Paros, Tinos, Karpathos, Kasos, Kythira, and Naxos. In the same year, Barbarossa raided Corfu and obliterated the agricultural cultivations of the island while enslaving nearly all the population of the countryside. However, the Old Fortress of Corfu was well defended by a 4,000-strong Venetian garrison with 700 guns, and when several assaults failed to capture the fortifications, the Turks reluctantly re-embarked and once again