TheRoyal Military Canal is a canal running for 28 miles (45 km) between Seabrook nearFolkestone and Cliff End nearHastings, following the old cliff line borderingRomney Marsh, which was constructed as part ofBritish anti-invasion preparations of 1803–05 againstNapoleon's planned invasion of the United Kingdom.

The canal was conceived byLieutenant-Colonel John Brown of theRoyal Staff Corps of field engineers in 1804, duringanti-invasion preparations, as a defensible barrier to ensure that a French force could not use the Romney Marsh as abridgehead. It had previously been assumed that the marsh could be inundated in the event of an invasion, but Brown argued that this would take ten days to implement and would cause massive disruption in the event of a false alarm. At a meeting on 26 September 1804, thePrime Minister,William Pitt the Younger, and theCommander-in-Chief of the Forces, theDuke of York, both enthusiastically endorsed the scheme.John Rennie was appointed consultant engineer, and Pitt personally persuaded the local landowners to agree to the new canal.

Royal Military Canal Act 1807
Act of Parliament
Parliament of the United Kingdom
Long title	An Act for maintaining and preserving a Military Canal and Road, made from Shorncliff in the County of Kent, to Cliff End in the County of Sussex, and for regulating the taking of Rates and Tolls thereon.
Citation	47 Geo. 3 Sess. 2. c. 70
Dates
Royal assent	13 August 1807

Royal Military Canal Act 1837
Act of Parliament
Parliament of the United Kingdom
Long title	An Act for transferring and vesting the Royal Military Canal, Roads, Towing Paths, and the Ramparts and other Works belonging thereto, and all Estates and Property taken and occupied for the same, in the Counties of Kent and Sussex, and also the Rates and Tolls arising therefrom, in the principal Officers of His Majesty's Ordnance.
Citation	7 Will. 4 & 1 Vict. c. 20
Dates
Royal assent	30 June 1837

Construction was started atSeabrook, nearHythe inKent on 30 October 1804. By May 1805 only six miles of the canal had been completed; William Pitt intervened and the contractors and Rennie were dismissed. The work was resumed by theQuartermaster-General’s department with Lt-Col. Brown in command. Civiliannavvies dug the canal itself, while soldiers built the ramparts.^[1] It was constructed in two sections: the longer section starts at Hythe and ends at Iden Lock inEast Sussex; the second, smaller section, runs from the foot ofWinchelsea Hill to Cliff End. The two sections are linked by theRiver Rother (Eastern) andRiver Brede. Artillery batteries were generally located every 500 yards (460 m), where the canal was staggered to create a salient, allowing the guns toenfilade the next stretch of water. A military road was built on the inland side of the canal, and crossings consisted of moveable wooden bridges.^[2] Any troops stationed or moving along the military road would have been protected by the earthen bank of theparapet, which was piled up with excavated soil. The canal was completed in April 1809 at a total cost of £234,000;^[3] it was hoped that tolls for use of the waterway and road would help to defray the cost. In addition to these works, a number ofMartello towers were built to protect the vulnerablesluices that controlled the water level in the canal, being towers numbers 22 to 27 and 30, three of which are still standing.^[4]

Royal Military Canal Act 1867
Act of Parliament
Parliament of the United Kingdom
Long title	An Act to authorize a Sale or Lease of the Royal Military Canal and its collateral Works; and for other Purposes.
Citation	30 & 31 Vict. c. 140
Dates
Royal assent	20 August 1867

Despite the fact that the canal never saw military action, it was used to try to control smuggling from Romney Marsh. Guard houses were constructed at each bridge along its length. This met with limited success because of corrupt guards.^{[citation needed]} Although a barge service was established from Hythe to Rye, the canal was abandoned in 1877 and leased to the Lords of the Level of Romney Marsh.

During the early stages ofWorld War II, duringpreparations for a threatened German invasion, the canal was manned by31st Independent Brigade Group, who fortified each salient with a concretepillbox andbarbed wire entanglements; numerous pillboxes survive today.^[5] In the German invasion plan, codenamedOperation Sea Lion, theparatroopers of the7th Flieger-Division were tasked with a parachute landing to secure crossing points across the Royal Military Canal on the first day of the invasion.^[6]

A publicpath runs alongside the entire length of the canal, forming part of the longer 163-mile (262 km)Saxon Shore Way. Aside from being historically significant in its own right, the path passes by numerous WW II pillboxes and the unusualacoustic mirrors, the historiccinque port towns ofHythe,Winchelsea, andRye, the 12th centurySt Rumwold's church, andLympne andCamber castles.

The canal is an important environmental site, and passes through severalSites of Special Scientific Interest. TheEnvironment Agency is thenavigation authority and uses the waterway to manage water levels onRomney Marsh andWalland Marsh. It is important for fish and other wildlife, includingkingfishers,dragonflies, andmarsh frogs.

• Canals of the United Kingdom
• History of the British canal system
• British anti-invasion preparations of 1803–1805

• The Canal page at the Romney Marsh Countryside Project website
• images & map of mile markers seen along the Royal Military canal

50°58′39″N0°45′19″E / 50.977617°N 0.755215°E /50.977617; 0.755215

• History of Kent
• Napoleon's planned invasion of the United Kingdom
• Fortification lines
• Canals in Kent
• Canals opened in 1809

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