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The art of defence

One of England’s finest surviving coastal fortresses, together with the fortress at St Mawes, Pendennis Castle’s history of defence spans nearly five centuries.

© English Heritage: Pendennis Castle

Constructed under the reign of King Henry VIII, Pendennis Castle and St Mawes Castle were built as part of a chain of forts installed between 1539 and 1545, to counter an invasion threat from Catholic Europe. Between them, Pendennis and St Mawes guarded the Carrick Roads – now known as some of the UK’s finest sailing waters, but once an important anchorage point.

Top Left: © English Heritage: St Mawes Castle| Top right: © English Heritage | Bottom left: Adam Gibbard/Visit Cornwall: The Carrick Roads | Bottom right: © English Heritage

As he implemented a national programme of military and naval preparations, these two now iconic castles played a crucial role in the king’s plans, especially given that the Carrick Roads – a deep estuary at the mouth of the river Fal – would have made the perfect place for an enemy to establish a foothold during an attack. Built with gun forts that would rain fire down on any aggressor, Pendennis had a circular design that gave defenders the ability of all-round fire from guns mounted at different levels. It was fully garrisoned, but only when a threat was deemed imminent. One such time was during the planned Spanish invasions of 1574, 1579, 1588 (the ‘Great Armada’) and 1596-97. On the final occasion, the fleet had intended to disembark troops at Pendennis and capture the estuary. Although the attack never came, the threat nonetheless forced Queen Elizabeth I to review the defences. So it was that by 1600, engineer Paul Ive had surrounded Henry VIII’s castle within a much larger fortress, thus defending the entire headland.

More improvements still came in 1627, as England attempted to influence the course of the Thirty Years War in Europe, with Sir Bernard Johnson creating a new rampart and ditch across the peninsula. But it wasn’t until the 1640s, during the First Civil War, that Pendennis was first put to the test. Falmouth was an important port for King Charles I’s army, and in 1646, Pendennis became one of the Royalist army’s final strongholds against the Parliamentary army. In fact, around 1,000 soldiers and their families were besieged there for five months, only agreeing to surrender when their food supplies ran out.

© English Heritage

The following centuries were largely uneventful for Pendennis; ongoing war with the Dutch and the French ensured it was always manned by a small garrison. New guard barracks and a gateway were built around 1700, then in 1714, as coastal defences were reviewed and engineer Colonel Christian Lilly deemed Pendennis to be in a ‘ruinous’ condition, the old rampart was re-formed, new guns were installed, and new buildings erected.

The late 1700s saw more troops – the locally raised Miners’ Militia – garrisoned at the castle, during the American War, and during the Napoleonic War (from 1793 to 1815), the garrison become permanent. Defences were bolstered with five raised gun batteries overlooking the landward approaches; a new sea battery (known as Half Moon Battery) was built outside the fort to the south, while more buildings were erected including a hospital and store buildings.

The tale of Pendennis follows a similar pattern for its more recent history too – first falling into decline after the defeat of Napoleon at Waterloo, before seeing the installation of more powerful guns during an arms race between England and France during the late 1850s. In the 1860s, Pendennis was considered a lower strategic target for enemy forces, and so received little attention in the nationwide programme of fort-building.

It did see some improvements from 1880 to the dawn of the 20th century, one major change being the introduction of a submarine minefield across the entrance to the Carrick Roads, with remotely detonated mines. But it was Falmouth’s designation as a ‘Defended Port’ in 1887 that resulted in a number of new defensive changes, including breech-loading guns to replace their muzzle-loaded predecessors, accurate range finders, searchlights to aid night fights, and telephones and electricity – enabling effective communication from the fort.

© English Heritage

These changes, among others, required a permanent staff, and in 1902, new barracks were built for the 105th Regiment Royal Garrison Artillery. As the first of two World Wars broke out, Pendennis became the command centre of coast artillery forces on the west Cornish coast. Defensive points and trenches helped protect it in the event of an invasion, and troops – in their thousands – arrived there for training before shipping off to the fronts in France and Belgium.

A similar story can be told for the Second World War; in 1939 the castle resumed control of west Cornwall’s coastal defences. Threats from torpedo boats were countered by twin 6-pounder and 12-pounder guns, while long range defences were installed against ships, with guns in new covered positions at Half Moon Battery. After the end of the Second World War, it continued to be used for training, until 1957, when it returned to the guardianship of the Ministry of Works for opening to the public.

© English Heritage

With such a fascinating history as one of Cornwall’s key coastal defences, a visit to this iconic Cornish site is always interesting. Today, visitors can take a tour through what is, despite our simplified version above, a very complex history of conflict. Its position above the sea affords dramatic views to Falmouth, across the Carrick Roads and out to sea; from various points, it’s easy to see why, nearly 500 years ago, Henry VIII first chose Pendennis headland as a key link in his chain of coastal defences.


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