Octavian was defeated at sea in the Battle of Messina (37 BC) and again in August 36 BC. But Octavian's lieutenant, Agrippa, a commander of great talent was able to destroy Sextus' fleet a month later at the Battle of Naulochus in September 36 BC. Octavian imposed a heavy indemnity on Sicily of 1,600 talents and the cities that had resisted him were harshly punished. Thirty thousand slaves in Sextus Pompey's service were captured; the majority were returned to their masters, but about 6,000, who had no masters, were impaled.