When the press says "gunboat diplomacy," the Defender-class Armoured Air Cruiser is the gunboat they mean. Until the raising of the third HML Leviathan in 1906, the Defender's familiar 'beak,' four stacks, and the brass tubing of its Swann stabilizer could be sketched accurately by any schoolboy. With its massive primary and secondary armament, the Defender-class remains equivalent to the aerial battleships of lesser powers.