Mahon & Gibraltar besieged during the Seven Years’ War

Scarce broadsheet maps of two of Britain's Mediterranean possessions, published when both were under siege during the Seven Years War (1756-63). At the top is Gibraltar, orientated with north to the left, with a 40-point key listing features of both the British defences and the Spanish siege lines crossing the neck of the peninsula. To the right is an inset chart of the western Mediterranean. Underneath is Mahon Harbour, then Britain's most important naval base outside the British Isles, orientated with north to the bottom right, with a 32-point key. At the mouth of the harbour is St Philip's Castle and Fort Marlborough, the latter being the only part of the British defences still extant.