The conquest of Constantinople (nowadays Istanbul) by the Turkish empire, in the middle of the XVth Century, and it´s advance towards central Europe alongside it´s progressive maritime domination, meant a threat to the control of the Mediterranean Sea.
At the beginning of the XVI Century, in order to stop this advance, the Spanish Emperor Carlos V decided to conquer Tunisia, in order to close the access to the Turkish galleys to the Western Mediterranean.
As a revenge to that conquest, the Turkish fleet attacked and destroyed Mahón in 1535 (and later Ciudadela in 1558). That´s the reason why it was decided to fortify the island, by building a castle, that would house a permanent garrison.
In 1571 with Spain´s victory over the Turkish fleet, at the naval battle of Lepanto, the threat vanished, then the pirate activities would replace it, and would cause a lot of trouble to navigation and trade in later centuries.
Director Lieutenant Colonel Bartol