England’s Front Line: the evolution of Dover Castle through the centuries

Not many historical buildings have had such a varied history as Dover Castle, which has marked the front line of England’s defences when invasion has loomed from continental Europe. The name Dover comes from the old French word ‘Douvres’, meaning water, as Dover is the closest point between England and France at just 22 miles. Whether the threat has been presented by a little-known French noble or the Third Reich, Dover Castle has served as England’s front line of defence for generations, against different weaponry and enemies.

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Dover marks the closest point from England to France, right on the south-eastern tip of Kent. Dover’s location has dictated why the town, and more importantly the castle, have been of such strategic and defensive important in England. Source: Wikipedia.

Strait of Dover - Wikipedia
The first large-scale remodelling of Dover castle was undertaken by King Henry II in the 1180s. Henry designed the castle primarily as a place where he could lavishly entertain visitors, but wisely, he also knew the strategic importance over Dover being built into a defensive stronghold. Some walls were over 6 metres thick, and in the 12th century the castle was a towering behemoth at over 25 metres tall.

Henry II’s building work was continued by his descendants, King John and Henry III, and this work would prove vital. Dover’s new defences were tested extensively between 1216 and 1217, where with the support of English nobles rebelling against King John, Dover Castle was subject to a 10-month siege by an invasion force led by Prince Louis of France. Fortress Dover had to resist bombardment from catapults, tunnels dug out under the castle by French engineers, and hand-to-hand fighting in the tunnels. Eventually, the siege ended and Dover Castle had resisted its first major attack.

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The central keep at Dover Castle, built under the instruction of Henry II in the late 12th century. This three-storey keep lies at the heart of the castle and its defences. Source: Britain Express

In the early nineteenth century, England was constantly on alert due to the imminent threat of invasion from Napoleon’s France. Consequently, one of Britain’s most astute military engineers, William Twiss, was tasked with strengthening Dover’s defences. One of the biggest problems Twiss faced was that there was no quick way to get troops from the castle’s barracks to the beach. Troops would have to descend over a mile of twisting, turning, slippery pathways to reach the beach, which was not sufficient for repelling an invasion.

Therefore, Twiss took advantage of the White Cliffs of Dover. The soft chalk made it relatively straightforward for Twiss to carve a tunnel into the rock, which cut the journey to the beach from just over a mile to a few hundred feet. Twiss’ ‘Grand Shaft’ comprised three spiral staircases, which allowed one thousand soldiers to make it down to the beach in just twelve minutes. Although the invasion never came, Dover was on the front line once again having been modified to repel Napoleonic France.

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The ‘Grand Shaft’ staircase, designed by Twiss during the Napoleonic wars. The shaft has three intertwining staircases in it, meaning that troops could get down to the beaches to meet attackers in a third of the time. Source: Western Heights Preservation Society

Almost 150 years later, Dover Castle was called into action again. The Napoleonic era tunnels were brought back into service, where a British naval command centre was established in 1939 during the Second World War. Dover’s tunnels soon called into action, and contributed significantly to Britain being able to maintain its war effort. Without the Dunkirk evacuations of May and June 1940, it is unlikely Britain would have been able to sustain a war effort against the superior armies of Nazi Germany.

Dover’s tunnels housed the headquarters of Vice-Admiral Sir Bertram Ramsay, the man tasked with heading Operation Dynamo. In fact, the operation received its codename from the ‘Dynamo Room’ in Dover Castle’s secret underground tunnels where the operation was planned. Although Ramsay resigned himself to the fact that he may only be able to save 30,000-40,000 of almost half a million men from Dunkirk, over 338,000 British and French troops returned safely to Britain. Unbeknown to many, Dover Castle played a vital role in saving the free world from Nazi tyranny.

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An operations room from the secret wartime tunnels beneath Dover Castle. Rooms such as this are where Vice-Admiral Ramsey and his staff planned the evacuation of Dunkirk, which proved to be pivotal in the course and outcome of the Second World War. Source: English Heritage

Later, during the Cold War, Dover’s secret wartime tunnels were transformed from wartime operations rooms and a hospital to a nuclear bunker. Dover’s tunnels were made one of Britain’s Regional Seats of Government during the Cold War, where important individuals were to head in the event of nuclear fallout. Beneath the surface of the castle lay sleeping quarters, radio rooms and kitchens, where life could somewhat go on if the worst were to happen.

The tunnels also housed a communications room, where radio operators were to communicate with what remained of the outside world if nuclear war came. However, during the 1970s it was discovered that the White Cliffs’ permeable chalk would offer little protection against nuclear radiation, so the bunker was abandoned. In the late 1990s, English Heritage were simply handed the keys to the Cold War tunnels, and told nothing. Due to classification issues, little is known about this stage in Dover Castle’s history, but hopefully more information about Dover in the Cold War will be released in the near future.

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The staircase going down to the ‘Dumpy’ level tunnels beneath Dover Castle. The rooms below would have housed civil servants, military personnel, the fire brigade, police staff, the BBC and many other important figures in the event of nuclear fallout. Source: The BBC

Over the previous eight centuries, Dover Castle has been at the heart of England’s defences from foreign invasion. Whether this be against medieval French nobles, Napoleon Bonaparte, Hitler’s Nazis or a nuclear power, Dover’s defences were adapted to defend this island nation from one of its most vulnerable points. Without the defensive adaptations made at Dover Castle over the years, today Britain may have been a very different place.

By Miles Clayton

Miles is our resident blogger here at History Indoors. He is an a Final Year student studying Modern History at the University of Essex and researches the positive experiences of British children on the Home Front during the Second World War, with oral histories sitting at the heart of the research. If there are any questions you have on this topic that you would like to see answered, please post them in the comments section below and we will be happy to answer them!