Fort Rinella was one of four 100-ton gun batteries built in Malta and Gibraltar for the protection of the harbours. These forts became necessary with the building of two powerful Italian battleships; the Duilio and Dandalo, both armed with four 100-ton guns each in revolving turrets. At the time, Britain used the Mediterranean as a quick route to India and it was feared that the growing naval power of Italy might tip the balance of power in the region.