After a short siege, the Saracens were able to storm the seaward walls, overcome the Thessalonians' resistance and take the city on 29 July. The sacking continued for a full week, before the raiders departed for their bases in the Levant, having freed 4,000 Muslim prisoners while capturing 60 ships, and gaining a large loot and 22,000 captives, mostly young people. In the event, most of the captives, including John Kaminiates, who chronicled the sack, were ransomed by the Empire and exchanged for Muslim captives.