Pendennis and St. Mawes – Twin Castles on the Fal Estuary

St Mawes Castle with Pendennis in the Distance

Pendennis and St. Mawes - Twin Castles on the Fal Estuary


Falmouth Harbour is a deep natural expanse of water that has provided anchorage for centuries, and traditionally, like other coastal communities around the country, protection against any threat of foreign invasion was left in the hands of local lords, but the 16th century saw these simple defences become inadequate when the threat of invasion became more serious after King Henry VIII upset the Pope and his Roman Catholic friends.

The failure of Henry’s wife, Catherine of Aragon, to provide a male heir prompted Henry to do something about it, and under normal circumstances, it would have been easy enough for the king to do what he wanted, and that was to divorce Catherine and marry the new love of his life, Anne Boleyn – but these weren’t normal circumstances. When Henry asked Pope Clement VII to annul the marriage he refused, due in no small part to the fact that he was under the thumb of Charles V, the Holy Roman Emperor who had taken control of Rome – and Charles was Catherine’s nephew.

In 1533, Henry secretly married Anne Boleyn, and left the Pope with no option but to excommunicate him from the Catholic Church. The following year Henry forced through the Act of Supremacy which made him the Supreme Head of the Church of England thus leaving the Pope with no religious authority at all in England. Henry then wasted no time in divorcing Catherine – but he must have known that there would be trouble ahead.

The Pope was eventually compelled to act, and in 1538 issued an order to depose the King of England. Francis I of France, and Charles V, (who was also king of Spain as well as Holy Roman Emperor) posed the main threats, and to deal with them Henry needed to improve his vulnerable defences along the south coast – and the entrance to the Fal Estuary was one of them.

The Mouth of the Fal Estuary looking towards St Anthony Head


The intention was to build five castles at the mouth of the estuary, but only two were completed, which may explain why there isn’t one at St. Anthony Head. The peninsula at Pendennis and the headland of St Anthony guard the entry to Carrick Roads (the large area of water at the mouth of the Fal Estuary) but the siting of the castle at St Mawes was also able to protect the anchorage of the Percuil River.

Work started on building the two castles in 1540 and took about two years to complete. The word ‘castle’ is a bit misleading really because they weren’t built with repelling an army of archers in mind, but with big guns (or cannons to you and me). A better term would probably be Artillery Fort.

Both Henrician Castles, as they are sometimes called, were similar in design but not identical, so they’re not really twins either. Pendennis was built as a circular keep surrounded by a gun platform and is entered via a bridge over a dry ditch and through a forebuilding that was a late 16th century replacement for the original gatehouse.

The Keep at Pendennis Castle
The Forebuilding

At St Mawes, the keep has three semi-circular bastions that give it a clover-leaf like appearance, and has been described as “the most perfect survivor of all Henry’s forts”. There’s no doubt that it’s a good-looking castle, if it can be described that way, but it occupies a much smaller area than Pendennis and somehow doesn’t seem quite so formidable.

St Mawes Castle


The first captain of Pendennis Castle was John Killigrew, a member of an illustrious family from Arwenack (now a part of Falmouth), and probably the man who oversaw its construction. The family continued to be captains of the castle for the next two generations and it was another member of the family, also called John, who created the town of Falmouth under the peninsula’s protection around 1613. There’s a monument to the Killigrew family opposite what remains of the original family home.

The Killigrew Monument

Thanks to the complicated world of religion and European royal families, relations with France and Spain had improved by the time Elizabeth was crowned Queen of England in 1558. However, her rejection of marriage to King Philip of Spain started a downward spiral between the two countries which wasn’t helped by West Country sailors like Drake and Hawkins plundering Spanish ships and handing over some of the proceeds to Her Majesty.

In 1569 the inevitable happened and England and Spain were at war. For both Pendennis and St Mawes it meant adding stone ramparts and bastions for extra protection, as well as increasing the garrisons and artillery.

Although the Armada was defeated in the summer of 1588, it didn’t stop Spanish raids along the Cornish coast including the destruction of the Killigrew family’s house at Arwenack in 1593. In August 1595 four Spanish ships arrived in Mounts Bay and sacked Penzance, Newlyn and Mousehole, but in 1597 a planned attack on Pendennis by a fleet of Spanish ships and 20,000 men were was thwarted by bad weather.

The Upper Gun Room at Pendennis


The Virgin Queen’s death in 1603 led to the end of the Tudor dynasty and the uniting of the Scottish and English crowns under James VI of Scotland, who also became James I of England. When he was succeeded by his second son, Charles I, the threats to the two Cornish castles didn’t come from European royal families, but from within England itself.

In 1642 Civil War erupted between Charles I and Parliament, with the South-West of England supporting the monarchy. As the Parliamentarians started to gain the upper hand, the West Country became further and further isolated, and Pendennis was strengthened in anticipation of harbouring the King. He did come, but not for as long as expected.

In August 1646 the castle was one of the last Royalist strongholds to surrender after enduring a 5-month siege. The King had not only lost the war, but he was also about to lose his head, and for the first and only time in our history, the country became a republic.

The Expanding Fortress at Pendennis


The 18th and 19th centuries saw both castles having to be upgraded when problems with our neighbour across the channel reared its ugly head again. As if French support for the revolutionaries in the American War of Independence (1775-83) wasn’t bad enough, there followed a revolution much closer to home when the Bastille was stormed on the 14th July 1789.

The French Revolution spawned a new leader in Napoleon Bonaparte who was keen to form a new empire right across Europe under the same rules that were now operating in France. After making an early uneasy truce, the gloves came off in 1803, and Britain and France were at each other’s throats again. The Napoleonic Wars lasted until 1815 when the emperor was finally defeated at Waterloo.

During the Napoleonic Wars, Pendennis saw a permanent garrison installed with improved barracks; and both castles upgraded their defence capabilities with much stronger gun batteries. As was the norm though, when the threats receded, the castles started to fall into disrepair again.

By the second half of the 19th century, thanks to its important transatlantic shipping trade, Falmouth had become one of the most important ports in England, which meant improvements at the castles were needed again, but times had moved on since the firing of cannon balls. Instead, an electrically operated minefield was laid across the river and operated from both Pendennis and St Mawes.

Looking across to St Mawes from Pendennis


At the beginning of the 20th century a new garrison was installed at Pendennis and new barracks were built to house them, but across the water, the re-establishment of the battery at St Anthony Head had the effect of making St Mawes obsolete, but it was brought back into use as a barracks when the First World War broke out in 1914. Pendennis built extra reinforcements, but in the end neither St Mawes nor Pendennis saw any action during WWI.

The 1902 Royal Garrison Artillery Barracks

The war proved that St Mawes wasn’t really suitable for modern warfare and in 1920 it was transferred to the Ministry of Works who opened it up to visitors – but it wasn’t quite over yet. World War II saw it brought back into action and used as an anti-aircraft base, and Pendennis had a bigger role to play defending the estuary against German E-boats, as well as playing an important role in preparation for the Normandy Invasion. When the war was over St Mawes was decommissioned and Pendennis followed suit in 1956.

Half-Moon Battery at Pendennis
The Half-Moon Battery 6 inch Gun


When the castles came to the end of their useful life they came under the protection of the state, and any unwanted modern buildings were cleared away. Both sites were opened up to the general public, and today, both castles are looked after by English Heritage.

In this post I’ve outlined the history of the two castles, and there is plenty here for military history buffs to see, but like so many defensive positions, they occupy commanding locations, and for many that’s a good enough reason to come. As you’ve probably already gathered by now, St Mawes is smaller, but it lies on the beautiful Roseland Peninsula and I’ll be covering more of the area in future posts.

As for Pendennis, the views are exceptional: The headland is surrounded by water and the views up Carrick Roads, across to the Roseland Peninsula, and down the Cornish coastline towards The Lizard will take your breath away, even if the wind doesn’t.

Looking up Carrick Roads from Pendennis

Both castles are in extremely good condition: They are definitely not ruins – but neither were they practical enough to be transformed into stately homes. St Mawes can be reached by ferry from Falmouth, but there’s more to see at Pendennis if I’m being honest. Even the castle here isn’t particularly big and you’ll probably find yourself wandering around the bastions, batteries, and barracks more than you will the castle itself; but if you come to Falmouth without visiting Pendennis Castle you’ll be missing the reason why Falmouth exists in the first place.


28 thoughts on “Pendennis and St. Mawes – Twin Castles on the Fal Estuary

  1. Alli Templeton

    Back from Northumberland now (more’s the pity!), but looking forward to catching up with my blogging friends. I agree with you that they’re not castles as such, more forts being Henrician, although in some ways Pendennis looks more the part. Nevertheless, they’ve clearly got some great stories to tell and it’s good to know how they fit in with the royal politics and conflicts over the centuries. Being royalist strongholds, at first I wondered why they hadn’t been ruined by Cromwell, but then I know the parliamentarians decided to retain some fortresses for the defence of the nation, so I guess in that respect their locations would have saved them. And I couldn’t help but feel that gun room is slightly reminiscent of a scene from a tall ship’s gun deck. A great read, as always, Malc. 🙂

    1. Easymalc Post author

      Glad you’re all back safe and sound, even if Stuart’s wallet didn’t come back with you. No doubt you’ve brought back plenty of good memories though, and I’m expecting to see some posts about what you did up there in due course. Finding out about your degree success must have been the icing on the cake, and I don’t suppose it’s a holiday you’ll forget in a hurry.

      I’m glad you’ve had a chance to take a look at Pendennis and St. Mawes. As you say, they may not be castles in the true sense, but they’re in a beautiful location, and worthy of a visit for that reason alone. Thanks, as always, for your kind comments Alli, and I hope you don’t find it too hard coming back down south – and even back down to earth after what must have been quite a fortnight 😊

      1. Alli Templeton

        Many good memories, Malc, yes, and happily we came home to the wallet. Someone kindly handed it in to the pub next door to the Sill where he lost it, and they posted it back home. So that worked out well. Posts to come, of course, about Northumbrian medieval history and castles. But we all wish we didn’t have to come back down south – it’s really a come down after two weeks of peace, serenity, castles and beautiful landscapes. Even little Nathan is saying ‘I’m sad that were back from Northumberland’.

        Nice to see these two forts/castles in such a gorgeous location, anyway, and I enjoyed the read as I always do. 🙂

        1. Easymalc Post author

          I’m pleased that the wallet followed you back home. It restores faith in human nature if nothing else, and I’m certainly looking forward to see where you’ve been 🙂

  2. Toonsarah

    Another of your excellent history lessons Malcolm 🙂 The castles look impressive but it’s the coastal scenery I particularly like the look of 🙂 And your opening photo is a stunner!

    1. Easymalc Post author

      I’m glad you enjoyed it Sarah, and thanks for your compliment on the opening image 🙂

  3. starship VT

    Prior to reading this excellent blog, I had never before heard of Pendennis or St. Mawes Castles. I enjoyed reading about them, and can appreciate the many layers of history surrounding them. Looks like you had great weather the day you visited them. Great photos!

    1. Easymalc Post author

      Thanks Sylvia. It’s always good to hear from you. I’m glad you enjoyed reading this one, but in actual fact I had two good days weatherwise because I visited them on separate occasions 🙂 I always appreciate your comments about my photos because you’re not so bad yourself 🙂

    1. Easymalc Post author

      And thank you for your lovely comments Luisa. You know how much I value them 🙂

        1. Easymalc Post author

          That’s good to hear. Thank you. Have a lovely evening and weekend yourself- and keep those wonderful posts coming 🙂

    1. Easymalc Post author

      Thanks again for your kind words Francesc. I certainly don’t believe I’m a master of anything, but if you think I am then that’s more than good enough for me 🙂 You always seem to be able to give me a lift when I need it the most. Thank you 🙂

      1. Francisco Bravo Cabrera

        Thank you Malc, you bring history to life in a most agreeable manner and with incredibly beautiful illustrations, that, my friend, I call mastery! Cheers fot your kind words and enjoy the weekend!

  4. scooj

    Perfect. I’m sure you knew I’d love this post. As a child I could see both castles from my grandparent’s house in Flushing, although now I think about it, Pendennis might have been a bit round the corner. But out in boats you could easily see both.

    1. Easymalc Post author

      I was hoping you would see this one because I thought it might bring back some memories 🙂

  5. equipsblog

    Lovely retelling of many centuries of history–not an easy task. We have a Falmouth in Massachusetts, Maine, and Virginia (that I can find so far).

    1. Easymalc Post author

      Thanks Pat. I really appreciate your comments. It can’t be any coincidence of course that so many West Country towns have spawned cousins across the pond 🙂


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