Blunting a massive attack by sea (by the Royal Navy) and land (by French Royalists) in 1794, the small but strongly built round defensive tower held by Frensh Revolutionary forces, at Cape Mortella, on the north coast of Corsica, only fell when the wooden roof was set on fire. So impressed was the British Admiralty with the firepower potential and near impregnability of the tower, that it ordered improved versions to be built to guard its strategic coastlines and harbours of the United Kingdom.
In the shadow of very real Napoleonic invasion threats, 74 such towers were erected between 1804 and 1815 mainly along the south and east coasts of Ireland as well as another 103 around Britain and other British protectorates. The first tower was that built at Sutton, Co. Dublin. They were called ‘Martello’ Towers, misquoting ‘Mortella’.
Taking 6 months to build each one, at an average cost of £1,800 (€232,000 today but then labour was cheap), they are circular in shape, with 2-4-metre-thick walls, which were made from solid stone that was all sourced locally. The entrance doorway of the towers is up to 3.0 metres from the ground which meant access to the entrance was only made by a ladder. The ladder then could be removed to protect against an invader. A single cannon or brace of 18- to 24- pounder guns was mounted on a traversing roof platform. Another battery of guns was sometimes placed nearby.
They obviously acted as a deterrent as the Towers never fired a cannon in anger. Napoleon never invaded Ireland or England as he preferred land wars at which he was more competent than with naval warfare.
In Dublin there are still around 21 Towers that remain standing, but some are used as residences, shops, cafes and museums. In 1904, Oliver St John Gogarty rented the Sandycove Tower from the British War Office but had to wait until the military vacated before famously moving in with author James Joyce a co-tenant.
