In the fifteenth to seventeenth centuries, Gozo was prone to attacks by Barbary corsairs, along with most of Malta and other coastal areas in the Mediterranean and Europe. The harbour of Mġarr was commonly used by pirates to replenish with water and plunder the surrounding area. The worst attack occurred in July 1551, when Ottoman forces aided by corsairs tried to take over Malta but failed so they landed in Gozo, besieged the Cittadela and took almost the entire population of about 5000 to 6000 people as slaves (with the exception of a monk, some 40 elderly Gozitans and about 300 who managed to escape and hide). The slaves were taken aboard Ottoman ships from Mġarr Harbour itself.