How were Medieval Castles used in World War One?

In spite of the fact that they were constructed centuries before the start of World War One, Medieval castles had a role to play in that war. The grand old structures were useful defensive locations and could be used to attack the enemy. Here, Rowena Hartley tells us the story of two castles in southern England and how they were used in World War One.

The First World War saw a great change in British society as the population, economy, and industry were mobilized more than ever before. Yet it was not only the modern parts of society that were affected. Like many countries in Europe, Britain is dotted with the remains of old castles and forts that had been specifically made for defending and housing the troops from as early as the Middle Ages. With the threat of invasion from Germany, these old castles once again came into use as a place to house troops and mount defensive operations.

The south coast of England was naturally viewed as the most vulnerable to invasion as it lay closest to France. Therefore the southern ports and estuaries had to be defended against potential attacks. If they had fallen this would have given the Germans a safe place to harbor their ships; and in the case of an estuary, a river that could lead them to cities and strongholds further inland. Given the history of Britain, many of these ports have been the sites of vicious battles in the past and so were tactically significant for the same reasons they were in WW1.

The castles of Pendennis and St Mawes lay either side of the River Fal in Cornwall, South West England. Together they are a perfect example of how castles were repurposed from the medieval era to suit the purposes of modern warfare.

Pendennis and St Mawes under the Tudor Kings

In the mid-16th century, England was faced with the threat of invasion from continental Europe, although in that time it was from the Catholic countries of France and Spain. The Protestant king, Henry VIII, needed to have military buildings which could match his taste in powerful enemies; this led to an explosion in military spending and castle building especially along the south coast.

Pendennis and St Mawes were built from 1539 to 1545 with a central fort and gun tower to hold the cannons and a small garrison of soldiers. These types of castle were known as Device forts or Henrician castles; this meant they were comparable to the machine gun nests of trench warfare -good for killing at a distance but not easy to defend at close quarters. The cannons housed in Pendennis and St Mawes were capable of shooting half way across the River Fal so access to the estuary was near impossible without a ship incurring serious damage, especially as St Mawes was built in a clover-leaf pattern so that it could target as much of the estuary as possible. Yet the castles were vulnerable to an attack from the land, especially when compared to vast fortresses and towns of Europe that could survive sieges of months (such as Boulogne in France which withstood Henry VIII’s attack from July to September 1544).

Throughout the Medieval era there were various advances in castle building and naturally each country attempted to keep up with such advances. The greatest advancement of the 16th century was the creation of Trace Italienne, also known rather less impressively as star castles.  As the name suggests these castles were built without the straight squares or rounded curves of previous designs but rather with triangular walls that jut out from each other meaning that there were no blind spots for the guns as each triangle of the star could be seen and shot at from another of the triangles. In siege warfare this meant that the enemy could not use battering rams on any part of the castle without being victim to near constant attack.

After the death of King Henry VIII his Protestant successors, Edward VI and Elizabeth I, also suffered from the paranoia that the country would be invaded by the powerful Catholic countries. This meant that they began to adapt Henry’s castles to accommodate these architectural advancements. The cloverleaf design of St Mawes meant that it was already relatively well equipped for such warfare but Pendennis’ close central fortress was relatively vulnerable. So at the end of the 16th century Pendennis was redesigned to accommodate the technological advances. The central fortress largely remained unchanged in design but a new outer wall was added in the distinct star castle shape and a moat was dug with the excess earth being used to add height and padding to the outer fortifications. The castle was now able to defend the River Fal as well as survive an attack from the land.

Testing the Fortifications

However, unlike the castles of Europe (especially Italy where the Trace Italienne originated), English castles were rarely fell victim to sieges. It was only truly Elizabeth’s vastly expensive fortifications at Berwick-Upon-Tweed that defended the border between England and Scotland that actually tested the star castles on British soil. Although Elizabeth’s successor effectively united England and Scotland leaving this vast castle practically pointless other than as a testament to the expensive military tastes of the Tudors.

Therefore it was not until the English Civil War of 1642 to 1651 that Pendennis and St Mawes were tested, as they were Royalist strongholds supporting King Charles I against the republican Oliver Cromwell. The more recently developed Pendennis castle survived a 3-month siege and only surrendered when the men ran out of food. However, St Mawes failed to play to the castle’s strengths; instead the commander, believing that the republicans would attack by sea, aimed all of his guns towards the River Fal only to find Cromwell’s men knocking on his gates after a highly successful land attack. Despite their failure in the Civil War, no further changes were made to either castle, as they were believed equal to their role of defending their corner of the south coast.

From the 17th century to the early 20th century there were not too many serious threats of invasion, but Britain managed to successfully aggravate the majority of countries in Europe and beyond, which was enough cause to keep a small garrison to man both castles in case of invasion. No great changes were made to the outer fortifications but the insides of Pendennis castle were modernized in the Georgian era, especially as Falmouth, the port town at the foot of Pendennis castle, was benefiting from trade in the British Empire. St Mawes remained largely untouched and while Pendennis stands apart on a hill side the smaller sister castle is almost obscured by the residential buildings running up to its gates.

Improving and Rearming

Since the attack of the Spanish Armada in 1588, England had not faced too many serious threats of continental invasion and so, despite the events of the English Civil War, the castles of Pendennis and St Mawes had not been updated to deal with more modern weaponry. This changed with the outbreak of the First World War; although the Germans never landed on British soil the fear of naval attack was very great. Naturally new and purpose built defenses popped up in reaction to the First World War, such as trenches and “Pillboxes” (small camouflaged huts made of stone which provided a hidden shooting space). Yet, however newly built these defenses were, they were still basically lumps of stone and mud which were far less purpose built than the great defensive structures of the 16th century.

So why take the time to build new defenses when you live in a country dotted with well-fortified and highly serviceable castles in key tactical locations. Pendennis and St Mawes, as well as countless other castles across Britain and Europe had stood for hundreds of years and it is testament to the original architects and tacticians that very little was done to change them to suit the very modern First World War.

St Mawes saw no great structural changes. Machine guns and modern artillery weapons were installed and aimed across the River Fal to deal with any naval threat, and many of the old canons still remained in its grounds during the war. Deeper trenches were cut along the outside fortifications, although whether these followed previous patterns is unclear, and an old gunpowder store was then filled with the shells and bullets common to modern warfare. Across the river far greater changes were under way Pendennis was the command center for artillery defenses in West Cornwall and so needed up to date equipment in order to effectively defend the headland. Yet whilst some minor fortifications and underground bunkers were added little else was done to modernize the castle itself. Georgian buildings which stand across from the castle, but within the fortifications, housed soldiers who were being trained before leaving for the trenches of Belgium and France, but even here the buildings were only changed in minor details as this area had originally been built to house a garrison. Further small changes were made upon the outbreak of the Second World War, but after the modernization during World War One, little changed. The castle and barracks housed British and American soldiers who updated a few guns and installed equipment for identifying and firing upon submarines and enemy vessels.

There is a tendency to look upon the First and Second World Wars as revolutionizing warfare. After all, the advances in guns, machine guns and bombs were vast. Yet the centuries-old castles that dot the European countryside were still used to house garrisons and mount defenses. These castles were used to support soldiers as well as protect against gun and cannon fire, making them very useful defensive bases. I wouldn’t argue that they’d survive a modern nuclear attack but the bunkers would make them a far safer bet than nearby settlements. It appears that despite the increasing modernization of warfare, old rules still apply. The recent wars in the Middle East faced as much difficulty as the European empire builders centuries before, no one would invade America without expecting fierce grass roots resistance, and most people know not to attempt attacking Russia in winter. The trenches, tanks, planes and advanced artillery of the First World War may have changed the parameters of warfare but in many cases the scenery remained the same – and only slightly more camouflaged than the grand stone buildings of the medieval era.

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