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Royal Military Canal, Kenardington Bridge to Warehorne Bridge

A Scheduled Monument in Warehorne, Kent

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Latitude: 51.0518 / 51°3'6"N

Longitude: 0.8301 / 0°49'48"E

OS Eastings: 598450.639115

OS Northings: 131861.775156

OS Grid: TQ984318

Mapcode National: GBR RXT.STP

Mapcode Global: FRA D6MB.P6X

Entry Name: Royal Military Canal, Kenardington Bridge to Warehorne Bridge

Scheduled Date: 17 December 1986

Source: Historic England

Source ID: 1005125

English Heritage Legacy ID: KE 396 I

County: Kent

Civil Parish: Warehorne

Traditional County: Kent

Lieutenancy Area (Ceremonial County): Kent


A 1.64km length of the Royal Military Canal running from Kenardington Bridge to Warehorne Bridge.

Source: Historic England


This record was the subject of a minor enhancement on 14 August 2014. The record has been generated from an "old county number" (OCN) scheduling record. These are monuments that were not reviewed under the Monuments Protection Programme and are some of our oldest designation records.

The monument includes a length of the Royal Military Canal, an early 19th century defensive work, situated on low-lying ground on Romney Marsh, south of Warehorne. It runs north-east for 1.09km from Kenardington Bridge and then turns at an angle SSE towards Bridge Farm for the remaining 550m.

The length of canal is water-filled and the surviving features include the parapet; an earthwork bank on the west side, the Royal military road which survives as an earthen terrace, and the back drain, which survives as a water-filled ditch. On the west side of the canal are three Second World War hexagonal concrete pillboxes, which are included in the scheduling.

Source: Historic England

Reasons for Scheduling

The Royal Military Canal was a massive coastal defence work constructed between 1804 and 1809. Its purpose was to separate the expected landing and deployment of Napoleon's troops upon the coast of Romney Marsh and Walland Marsh from the interior of the country. The Government initially considered flooding the marsh but favoured the canal, which was the idea of Lt. Col. Brown, the Assistant Quartermaster-General. He carried out a survey and work commenced in 1804 at the height of the invasion scare, with John Rennie as consulting engineer (until 1805). The canal ran a total of about 28 miles from Shorncliffe Camp via Hythe inland to Appledore, to join the Eastern River Rother at Iden lock, from where it became part of first the Rother and then the River Brede, turning into a canal again from Winchelsea to Cliff End on the coast. Excavated earth formed the banquette and parapet on the landward side of the canal and behind this was an army supply route, the Royal Military Road. On the opposite side were the tow path and wharves. It also included a back and a front drain. The canal and parapets were so built that gun positions could be provided at the end of each length to flank the crossings. However by the time the canal was completed in 1809, the threat of invasion had passed, following Napoleon’s defeat at the Battle of Trafalgar, and it was to some extent obsolete. In 1810, the canal was opened for public use and tolls were also collected for use of the Royal Military Road. In the later 19th century public use declined. The last toll was collected at Iden Lock in December 1909. Today Iden lock is a sluice, so the main part of the canal is isolated. The eastern section of the canal is still in use for pleasure boats.

The Royal Military Canal was an important element in the Napoleonic defences of south-east England and is the only military canal in the country. It is a unique defensive work that bears significant testament to a period when modern Britain faced the most serious threat of invasion prior to the major conflicts of the 20th century.

The 1.64km length of the Royal Military Canal running from Kenardington Bridge to Warehorne Bridge survives well. It includes well preserved original features such as the Royal military road, the parapet, and the back drain. It will contain archaeological information relating to its construction and use.

The Second World War pillboxes are also of archaeological and historic significance. Pillboxes are small reinforced concrete or brick buildings of a diversity of shapes and forms, designed to house either infantry, anti-tank guns or field artillery. Some World War I examples survive in eastern and southern England, but pillbox construction mainly dates from late May 1940 as part of the rapid programme of anti-invasion defences initiated after the fall of France. Design principles born from the practical experience of British troops in France, led to a shell-proof concrete construction whose loopholes or embrasures in each facet gave all round cover. During the Second World War, they were located alongside other defensive structures either at vulnerable or strategically important nodal points, along the coast, on the communications network, around vital installations such as airfields, or arranged in linear defensive systems called Stop Lines that were intended to obstruct the enemy's advance. These examples on the Royal Military Canal are sited in a strategic position, with the canal serving as an obstruction to the enemy. They well illustrate the continued importance of anti-invasion defensive measures on this area of low-lying marshland near the Kent coastline during the 20th century.

Source: Historic England


Romney Marsh Countryside Project: Royal Military Canal website, accessed from
NMR LINEAR38. PastScape 1042908.,

Source: Historic England

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