Martello Tower

Martello towers (or simply Martellos) are small defensive forts built by the British Empire during the 19th century, from the time of the Napoleonic Wars onwards. They stand about 40 feet (12m) high (with two floors) and had a garrison of one officer and 25 men. Their round structure and thick walls of solid masonry made them very resistant to cannon fire, while their height made them an ideal platform for a single heavy artillery piece, mounted on the flat roof and able to traverse a 360° arc. A few Martello towers were surrounded by a moat for extra defence. They were used throughout the 19th century, but became redundant with the introduction of powerful rifled artillery. Many have survived to the present day, often being preserved as historic monuments.

Origins
Martello towers were inspired by a round fortress, part of a larger Genovese defense system, at Mortella Point in Corsica (see picture here). Since the 15th century, similar towers had been built at strategic points around Corsica to protect coastal villages and shipping from North African pirates. They stood one or two stories high and measured 12-15 m (36-45 ft) in diameter, with a single doorway 5 m off the ground that could only be reached by climbing a removable ladder. The towers were paid for by local villagers and staffed by watchmen (known as torregiani) who would signal the approach of unexpected ships by lighting a fire on the tower's roof. This would alert the local defence forces to the incoming threat. Although the pirate threat subsequently dwindled, the Genoese built a newer generation of circular towers which were used to ward off later foreign invasions. [1]

On 7 February 1794, the tower at Mortella Point was attacked by two British warships, HMS Fortitude (74 guns) and HMS Juno (32 guns) and was eventually captured by land-based forces under Sir John Moore after two days of heavy fighting. Vice-Admiral Lord Hood reported:

The Fortitude and Juno were ordered against it, without making the least impression by a continued cannonade of two hours and a half; and the former ship being very much damaged by red-hot shot, both hauled off. The walls of the Tower were of a prodigious thickness, and the parapet, where there were two eighteen-pounders, was lined with bass junk, five feet from the walls, and filled up with sand; and although it was cannonaded from the Height for two days, within 150 yards, and appeared in a very shattered state, the enemy still held out; but a few hot shot setting fire to the bass, made them call for quarter. The number of men in the Tower were 33; only two were wounded, and those mortally. [2]
The British were impressed by the effectiveness of the tower against their most modern warships and copied the design. However, they got the name wrong, misspelling "Mortella" as "Martello".