Device Forts | Martello Towers | 1859 Royal Commission | London Defence Positions | Timeline

Henry VIII's Device Forts

After Henry VIII's divorce of Catherine of Aragon left England politically isolated, a treaty between France and Spain in 1538 aroused fears of invasion. Although the threat was short-lived, it simulated the largest defence programme since Saxon times. Henry took a personal interest in the military engineering techniques of the time, and approved and ammended the designs himself. Some 30 works were started in 1539, but the key ones are the 10 device forts at Camber, Walmer, Deal Castle, and Sandgate in the South East, Hurst, Calshot, Sandown Blockhouse, around the Solent, and Portland, Pendennis, and St Mawes in the South West. All survive except Sandown, generally in the form of a central round tower surrounded by a variety of concentric elements. Short and squat, with normally 3 tiers of long-distance offensive armament and a couple of tiers of defensive armament. The bays had wide splays for easy traverse of the guns, walls were thick and curved to deflect shot, and the medieval portcullises, murderholes and drawbridges were perpetuated.

Martello Towers

While watchtowers had been built round the Mediterranean for centuries, and a series were built in the Channel Islands from 1778-1796, the name comes from a tower in Corsica. In Februrary 1794 a British squadron commanded by Sir David Dundas was frustrated by a tower at Cape Mortella, Gulf of San Fiorenzo, N. Corsica (now demolished). Impressed, the British built similar towers in Cape Town (1796), Halifax, Nova Scotia (1796), and Minorca (1798), but the most famous series arose when Dundas and others proposed building similar towers in Britain. Between 1805 and 1812 101 towers were built to resist the Napoleonic threat, though Trafalgar at 1805 reduced it considerably.

The 74 along the south coast from Folkstone to Seaford, were about 500-600 yards apart, 33' high and ranged from 13' to 6' thick due to an elliptical exterior, circular interior. Built of brick, with access at first floor level via a moveable ladder, they mounted a 24 pounder gun with a garrison of 25. Some towers on the higher ground at the eastern end of the chain also had 5 1/2" howitzers.

Many towers have been demolished over the years or swept away by the sea, but survivors include 1-2, 3,4-9, 13-15, 19,23, 24,25,28,30,55,60-62,64, 66, 73, 74. Peter Hibbs has a superb site about The South Coast Martello Towers which gives full details of both the overall planning and the state of every tower.

The 27 along the east coast from St Osyth Stone to Aldeburgh were similar, but mounted 3 guns (the Aldeburgh one was in a more elaborate quatrefoil shape).

Survivors include A,C,D,E,F,K,L,M,

At the same time the Royal Military Canal was dug to connect Hythe and Rye to isolate Romney Marsh from the high ground behind, though Napoleonic armies capable of crossing Europe's rivers would hardly be stopped by a 30' canal.

Other Martello towers were also built in Ireland, (20 including Donabate), Jersey (Kempt Tower), Orkney, Bermuda, Australia, and even Canada (including Carleton Tower, New Brunswick, and Murney Tower, Kingston, Ontario).

There is an older book and a newer booklet on the Martello towers, and an appreciation society

1859 Royal Commission

In 1859 a Royal Commission warned that Britain's coastal defences were inadequate to prevent invasion by Napoleon III if the Royal Navy were lured elsewhere. This resulted in a huge wave of building, with land forts on Portsdown above Portsmouth and sea forts around it, a ring of forts round Chatham, and isolated forts at Newhaven and Nothe, Weymouth. By the time they were completed in the 1880's it was clear that the French had not seriously planned to invade, and the Franco-Prussian war of 1870-71 removed the threat, so Prime Minister Palmerston, who pushed hard for their building, was widely criticised, and these forts are often called Palmerston's Follies.

London Defence Positions

The Royal Commission report believed that London was practically undefencible, but the view in the 1880's changed the emphasis to schemes based on simple earthworks for infantry and moveable armaments. The earthworks were to be thrown up in time of war, but were to be backed up with magazines at 5 mile intervals. On that basis the London Defence Positions were built along a 70 mile stretch of the North Downs from Guildford to the Darenth Valley. 13 sites were chosen, at Pewley Hill, Henley Grove, Denbies, Box Hill, Bletchworth, Reigate, East Merstham, Fosterdown, Woldingham, Betsoms Hill, Halstead, Farningham and North Weald. The design of each site varied, but they were never very elaborate, just a magazine and storehouses for the mobilisation of troops, with limited defences. Related stores were set up at Tilbury, Warley and possibly Caterham. They were quickly viewed as obsolete, and all were sold off in 1907, with the exception of Fort Halstead, now the MoD's explosives research department. I've visited Pewley Hill, near Guilford, and houses have been built on it, wheras Henley Grove has been well preserved as a youth centre, and could be seen on a Heritage Open Day. Reigate Fort is being restored by the National Trust with landfill tax money of all things! For the state of the others have a look at the PFS London Mobilisation Centres Gazeteer


Date Event ResultingFortifications
400 BC - 200 AD Roman Empire Portchester and Pevensey Castles, not covered here.
1066 Norman Conquest Many Norman castles, not covered here.
14th century Edward I conquers Wales Great Welsh Castles, not covered here. 
1533 Henry VIII breaks from Rome
1539 Invasion Crisis Henry VIII's Device Forts
1588 Spanish Armada
1642-1649 English Civil War Earthworks round Basing House
1667 Dutch raid Medway Medway forts
1792 Napoleonic Wars start
1794 Attack on Mortella Tower, Corsica
1803-5 Napoleonic Wars restart Martello towers on the East Anglian coasts, Dover Western Defences
1858 Armstrong's rifled breach loading gun, French ironclads
1859 Royal Commission Royal Commision forts
1914-1918 Nab Tower
1939-1945 Maunsell Sea Forts Pillboxes, Defence of Britain Project
1946-1996 See the Research Study Group, or David Farrant's site