Martello tower

Martello towers, sometimes known simply as Martellos, are small defensive forts that were built across the British Empire during the 19th century, from the time of the French Revolutionary Wars onwards. Most were coastal forts.

They stand up to 40 feet (12 m) high (with two floors) and typically had a garrison of one officer and 15–25 men. Their round structure and thick walls of solid masonry made them 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, and hence fire over, a complete 360° circle. A few towers had moats or other batteries and works attached for extra defence.

The Martello towers were used during the first half of the 19th century, but became obsolete with the introduction of powerful rifled artillery. Many have survived to the present day, often preserved as historic monuments.

In the second half of the 19th century, there was another spate of tower and fort building, during the premiership of Lord Palmerston. The Palmerston Forts are also circular in design and resemble Martello towers.

Martello towers were inspired by a round fortress, part of a larger Genoese defence system, at Mortella (Myrtle) Point in Corsica. The designer was Giovan Giacomo Paleari Fratino (el Fratin), and the tower was completed in 1565.

Since the 15th century, the Corsicans had built similar towers at strategic points around the island to protect coastal villages and shipping from North African pirates. The towers stood one or two storeys high and measured 12–15 m (39–49 ft) in diameter, with a single doorway five metres off the ground that one could access only via a ladder which the occupants could remove.

Local villagers paid for the towers and watchmen, known as torregiani, who would signal the approach of unexpected ships by lighting a beacon fire on the tower's roof. The fire would alert the local defence forces to the threat. Although the pirate threat subsequently dwindled, the Genovese built a newer generation of circular towers (the Genoese towers), that warded off later foreign invasions.

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