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Dover Castle in  Source: Alexey Fedorenko / Adobe Stock

Dover Castle: The Key to England at the Gateway to Europe

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Dover Castle has been dubbed the “Key to England” due to its location at the frontline of defense. Dover has played an important role in Britain’s history, both as a trading port and as the gateway to England, due to its being the closest town to continental Europe. Although the current castle dates to the Medieval period, the site in southeastern England may have been occupied as early as the Iron Age. Dover Castle served a military function up until the 20th century, after which it became a tourist attraction. 

Historians believe that the Classis Britannicus was based out of the Roman fort at Dover, which incidentally was not on the same site as Dover Castle. (RadoJavor / Deviant Art)

The Roman Invasion: Creation of a Roman Fort at Dover

According to the archaeological evidence available, the site of Dover Castle in Kent may have already been occupied between 800 BC and 43 AD during the British Iron Age. This is based on the discovery of massive earth ramparts and ditches which suggest that an Iron Age hillfort once stood on the site. In 43 AD, the Romans launched the invasion of Britain under Emperor Claudius and Dover became part of the Roman Empire. The Romans established their first port on the island at Richborough. By the second century AD, Dover too was developed into a port.

Around 110 AD, the Romans built a fort at the mouth of the River Dour, which they named  Dubris. This Latin name was eventually anglicized into Dover. It may be mentioned that the Roman fort was not built on the site of Dover Castle, which is located on higher ground. The fort is thought to have served as the base of the  Classis Britannicus(which translates literally to mean “British Fleet”). This was a provincial Roman fleet that was used to control and patrol the English Channel. At some point the construction of the fort was halted, but was restarted in 130 AD and completed once and for all. 

The most visible structure left by the Romans at Dover, however, is the lighthouse. This is an octagonal tower-like structure that was built on Castle Hill, where the Iron Age hillfort would have once stood. Another lighthouse was erected on the Western Heights, opposite Castle Hill, and a third, the  Tour d’Odre, was located across the English Channel in Boulogne-sur-Mer, France. The three lighthouses served as navigation markers for ships sailing in that area. The lighthouse on Castle Hill was eventually turned into the belltower of the Church of St Mary in Castro during the Anglo-Saxon period.

The Roman lighthouse, one of only three surviving Roman-era lighthouses, was converted to a belltower for the church at Dover Castle. (Alexey Fedorenko / Adobe Stock)

Saxon Origins and the First Norman Dover Castle

After the Romans left Britain in 410 AD, the site of the future Dover Castle was turned into a Saxon burh, or fortified town. This is supported by the discovery of a cemetery discovered during an excavation around the Church of St Mary in Castro in 1962. The discovery suggests that there was a community living nearby during the Anglo-Saxon period. Up until then, there had not been a castle in Dover, and it was only during the subsequent Norman period that the first Dover Castle was built.

In 1066 William the Conqueror defeated Harold II, the last Anglo-Saxon king, at the Battle of Hastings. Following their victory, the Normans moved to secure the southeastern coast of England so that they could have unrestricted access to continental Europe. Dover was therefore a strategic site in this plan and the Normans captured the port shortly after the Battle of Hastings. 

The Normans are recorded to have stayed in the town for eight days, during which they constructed a castle within the earthworks of the hillfort. Unfortunately, the remains of William’s castle have not survived, and therefore, it is impossible to know the appearance and size of the original Dover Castle.

The guest hall at Dover Castle. (HARTLEPOOLMARINA2014 / CC BY-SA 4.0)

Henry II Spared No Expense When Building Dover Castle

The current Dover Castle was built by Henry II during the 12th century. The complete rebuilding of the castle was undertaken between 1179/80 and 1189. Henry spared no expense in rebuilding Dover Castle. According to the Royal Pipe Rolls, or financial records, the king spent a total of £6300 to build the castle. Henry’s castle was not only an imposing defensive structure, but also contained a residential area fit for a king. 

It has been suggested that one reason for this was the fact that since the 1170 murder of Thomas Becket, the Archbishop of Canterbury, his shrine in Canterbury became an important pilgrimage site. Many pilgrims from the continent would have passed through Dover on their way to Canterbury, which is relatively close by. These included important figures, such as royalty and high-ranking clergymen. In 1179, for instance, Louis VII was at Dover, and was hosted by Henry at the Norman castle. Henry was probably embarrassed that he had to host a fellow monarch in an unimpressive timber castle, which motivated him to build a new, modern castle at Dover.

Interestingly, we know that Henry’s castle was built by a master mason named Maurice, who had also built the castle keep at Newcastle upon Tyne. Maurice built the castle’s inner bailey and towers, part of the outer bailey, and the great tower. Subsequently, Henry’s son, John, extended the castle’s curtain wall. These works began in 1207, not long after John had lost Normandy to the French. This loss meant that the French were now able to invade England from Normandy, and that Dover was now on the frontier between England and France. John was aware that he had to enhance the defenses at Dover.

The arrival of Louis VIII in England from the Chronica Majora. (Public domain)

Louis VIII and his Failed Invasion of England

In 1216, the future Louis VIII of France was invited by John’s rebellious barons to invade England, and to seize the throne from the king. In May that year, the French dauphin landed unopposed on the Isle of Thanet, the easternmost point of Kent, and immediately marched to Dover. 

The port city, however, was one of the few places still controlled by forces loyal to John. Dover Castle was held by Hubert de Burgh, who was later made the 1 st Earl of Kent. Hubert was not only a loyal servant of John, but also an experienced soldier, and, most importantly, an expert in siege warfare.

In July 1216, Dover Castle was besieged by Louis. The besiegers focused their assault on the vulnerable North Gate, and Hubert made every effort to counter their actions. When the French breached the walls by undermining the North Gate, causing the eastern tower to collapse, the defenders sallied out from the castle to block the gap with a temporary timber palisade. 

Ultimately, Louis was unable to take Dover Castle, and the siege was lifted on the 14 th of October 1216. This was the beginning of the end of Louis’ invasion. When John died five days later, many of the barons deserted Louis, preferring to support John’s son Henry III. 

Watercolor of Dover Castle. (Public domain)

Dover Castle Renovations Under Henry III

Following the failed siege by the French, Dover Castle was repaired. The eastern tower was rebuilt, and the North Gate was blocked. Apart from that, a massive program to upgrade the castle was initiated, by none other than Hubert himself. The castle’s outer curtain wall was strengthened, the defensive ditches were enhanced, and erected the Constable’s Gate. Hubert also enhanced the defenses at the site of the North Gate, which included the construction of two new towers, and the putting in place of an underground tunnel system that connected the different structures in this part of the castle.

Although Hubert became an extremely influential figure at the court of Henry III, John’s successor, he also made enemies. Eventually, Hubert fell victim to the plotting of his enemies, and was stripped of his titles. Dover Castle, which had been in Hubert’s hands till that time, was returned to the Crown. 

Henry’s direct control of the castle was maintained until July 1263, when it was captured by Simon de Montford, who led the barons against the king in the Second Barons’ War. After Simon’s death at the battle of Evesham in 1265, Dover Castle was besieged by the king’s forces. After a short siege, negotiations took place between Eleanor, Simon’s wife, and the future Edward I, Henry’s son, who was also Eleanor’s nephew. This led to the castle’s surrender to Henry.

Aerial image of Dover Castle against the backdrop of the English Channel. (Chensiyuan / CC BY-SA 4.0)

The Role of Dover Castle from the Middle Ages

Considering Dover’s strategic location, the castle retained its importance throughout the Middle Ages, and a garrison was maintained there continuously. Nevertheless, specific details about the castle during this period have not survived. It is known, however, that during the reign of Edward IV, the residential elements of the castle’s keep were upgraded. 

It is also known that in 1522, the Holy Roman Emperor, Charles V, was a guest at Dover Castle. Charles was in England for a six-week diplomatic visit, and met Henry VIII at the castle. Incidentally, Henry himself stayed at Dover Castle on several occasions. 

Following the English Reformation, the now Protestant kingdom of England was now at odds with Catholic Europe and was especially threatened by Spain and France. Therefore, the defenses at Dover were beefed up. No upgrades, however, were made to Dover Castle, a sign of its declining importance. 

By 1642, when the English Civil War broke out, the castle was garrisoned by a small force of 20 men. The castle was held by the Royalists, but majority of Dover’s population were Parliamentarians, and they easily captured the castle. Subsequently, the castle did not play a significant role in the war.

Cartoon of Napoleon with Dover Castle on a cliff on the English coast. (Public domain)

Regaining Importance: Dover Castle During the 18th and 19th Centuries

Dover Castle regained its importance as a defensive structure during the 18th and 19th centuries. During that time, France and England were regularly in conflict. Therefore, the defenses at Dover had to be enhanced. By that time, warfare had changed drastically, and Dover Castle had to be substantially modified to stay relevant. 

For instance, in response to bombardment from enemy cannons, the outer wall of the castle on the northeastern side was reduced in height, and backed by an earth rampart. This was meant to absorb the shock of cannon balls. The same was done to the castle’s eastern outer wall, later on at the end of the 18th century. 

Apart from that, new barracks were built, which could accommodate up to 800 infantrymen. Needless to say, these troops needed supplies to defend the so-called “Key to England”. Therefore, new gunpowder magazines were built in the castle. Additionally, the great tower was converted into a storage for gunpowder, shots, and other military supplies, while several gun batteries were built so that cannons could be mounted.

When the Napoleonic Wars ended in 1815, Dover Castle’s importance as a military fortification was reduced once again. Nevertheless, it still retained some defensive functions. For instance, some upgrades to the castle were made during the 1850s, following the ascension of Napoleon III, and fears that the French might try to invade England again. Even though a new fortress, Fort Burgoyne, was built in 1865, Dover Castle continued to be used for coastal defense, with four groups of large guns being installed during the 1870s. 

Winston Churchill at Dover Castle observation post in August 1940. (Public domain)

Dover Castle in the Modern Era

Dover was an important port for Britain during the First and Second World Wars, and Dover Castle played a part in these two conflicts as well. For instance, anti-aircraft guns were placed on the eastern curtain wall to counter the new threat of airships and airplanes. Apart from that, the underground tunnels were used as a naval headquarters. Operation Dynamo, which was aimed at evacuating British troops from France in 1940, was planned in these tunnels. 

In 1958, the Queen’s Own Cameron Guards, the last regiment to garrison Dover Castle, was withdrawn. This effectively marks the end of Dover Castle’s military functions. Nevertheless, the Constable’s Gate was retained as the residence of a senior officer until 2015. More interestingly, in the early 1960s, during the Cold War, Dover Castle was selected as one of the 12 Regional Seats of Government, in the event of a nuclear war. The castle’s underground tunnels were renovated to serve this function. This dreaded war, fortunately, did not happen, and the site was finally decommissioned in the 1980s. 

Around the same time Dover Castle was being prepared for a nuclear war, it was transferred to the Ministry of Works to be preserved as an ancient monument. Following the decommissioning of the site, Dover Castle was placed under the management of English Heritage. The historical importance of the castle is reflected in the fact that it is both a scheduled monument and a Grade I listed building. Today, Dover Castle is a tourist attraction open to the public. 

Top image: Dover Castle in  Source: Alexey Fedorenko / Adobe Stock

By Wu Mingren


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Wu Mingren (‘Dhwty’) has a Bachelor of Arts in Ancient History and Archaeology. Although his primary interest is in the ancient civilizations of the Near East, he is also interested in other geographical regions, as well as other time periods.... Read More

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