This sixteenth century wall, which comes down from the ancient Moorish Wall, past the Trafalgar Cemetery at the southern end of Main Street, was built in the reign of Charles V in 1552 by the Italian Engineer, Calvi. It was designed to defend the city after the attack of September 1540 by Turkish pirates, under the command of Barbarrossa, who took over 70 captives with the intention of selling them into slavery. The original wall dates back to the Moorish period at which time it climbed straight up almost to the very top of the Rock. When Charles V died, Philip II took over the building of the wall. Due to the close proximity of the wall to the town, he decided it would be better to continue the wall further away, hence the continuation starting at the Apes Den, named Philip II Wall.