Hurst Castle is an artillery fort established by Henry VIII on the Hurst Spit in Hampshire, England, between 1541 and 1544. It formed part of the king's Device Forts coastal protection programme against invasion from France and the Holy Roman Empire, and defended the western entrance to the Solent waterway. The early castle had a central keep and three bastions, and in 1547 was equipped with 26 guns. It was expensive to operate due to its size, but it formed one of the most powerful forts along the coast. During the English Civil War of the 1640s, Hurst was held by Parliament and was used briefly to detain King Charles I before his execution in 1649. It continued in use during the 18th century but fell into disrepair, the spit being frequented by smugglers.
Repairs were made during the French Revolutionary Wars and the Napoleonic Wars with France, and the castle was modernised to enable it to hold 24-pounder (10.8 kg) guns. Fresh fears of invasion followed in the 1850s, leading to heavier, 32-pounder (14.5 kg) armament being installed and new gun batteries being laid out on both sides of the castle. Technological developments rapidly made these defences obsolete, however, and a fresh phase of work between 1861 and 1874 created sixty-one gun positions in two long, granite-faced batteries alongside the older castle. These held very heavy weapons, including massive 12.5 inch, 38 ton (317 mm, 39,000 kg) rifled muzzle-loading guns. As the century progressed these too became outdated, and lighter, quick-firing guns were installed at the castle to replace them.
The castle formed part of a network of defences around the entrance to the Solent during the First World War, and was re-armed again during the Second World War. The military decommissioned the fort in 1956 and it passed into the control of the Ministry of Works. In the 21st century, it is run jointly by English Heritage and the Friends of Hurst Castle as a tourist attraction, receiving around 40,000 visitors during 2015. Coastal erosion has become a growing problem despite government intervention in protecting the spit. Four lighthouses have been built at Hurst from the 18th century onwards, one of which, a high lighthouse first opened in 1867, remains in active service.
In January 2021, local media reported that the castle was in urgent need of repairs due to coastal erosion, The World Monuments Fund included the castle on their 2022 World Monuments Watch list of most endangered sites.
In September 2022, it was one of six English castles included in a fundraising campaign by English Heritage to mitigate risks of destruction due to worsening coastal erosion. They hope to gather enough funds to repair and strengthen the sea walls around the castle. Modest defences based around simple blockhouses and towers existed in the south-west and along the Sussex coast, with a few more impressive works in the north of England, but in general the fortifications were limited in scale. Worsley's Tower, for example, built opposite the future site of Hurst Castle in the 1520s, was too small to hold powerful artillery and considered by surveyors in 1539 to be "one of the worst devised things" they had seen.
In 1533, Henry broke with Pope Clement VII over the annulment of his long-standing marriage to Catherine of Aragon. Catherine was the aunt of Charles V, the Holy Roman Emperor, who took the annulment as a personal insult. This resulted in France and the Empire declaring an alliance against Henry in 1538, and the Pope encouraging the two countries to attack England. An invasion of England appeared certain. In response, Henry issued an order, called a "device", in 1539, giving instructions for the "defence of the realm in time of invasion" and the construction of forts along the English coastline.
Hurst Castle was designed to protect the western entrance to the Solent, a body of water that led from the English Channel to the naval base at Portsmouth and, through Southampton Water, to the important port of Southampton. The castle was one of four fortifications that William Fitzwilliam, the Lord High Admiral, and William Paulet recommended building to strengthen the defences along the Solent; the others were at East and West Cowes, and Calshot. It was positioned on the Hurst Spit, a strip of shingle sheltering saltmarsh and mud flats, only across the water from the Isle of Wight. Temporary earthwork fortifications were erected on the site and, after the other three castles had been completed, work then began on Hurst in 1541 under the direction of John Mille, the financial controller, and probably Thomas Bertie, a master mason. Bertie was appointed as the castle's captain in 1542 and the work was completed by January 1544, at a cost of over £3,200.
thumb|left|Gun embrasure in the 16th-century castle
The result was a stone artillery fort with a central keep and three bastions, surrounded by a moat, capable of holding up to 71 guns. In 1547, however, Hurst was equipped with 26 artillery pieces–four made of brass and the remainder iron–comprising a two sakers, a culverin, a demi-cannon, a curtall cannon, two demi-culverins, six portpieces, four slings, two quarter-slings, and seven bases, three of them inoperable. A 1559 survey commented that Hurst Castle was essential for sending reinforcements from the mainland to the island, and noted that it was equipped with eleven brass and iron guns, with nine further broken guns, along with handguns, bows and arrows, pikes and bills. The survey observed that the castle was vulnerable to attack because it lacked flanking protection and had rounded walls, and that it was expensive to garrison because of its size, requiring a captain, his deputy, twelve gunners, nine soldiers and a porter.
Meanwhile, the invasion threat from France had passed and a lasting peace was made in 1558; government concerns shifted away from the south coast towards the Spanish threat to the south-west of England. By 1569, when Thomas Carew was serving as Hurst's captain, there were less than ten guns but the same size of garrison to that seven years before. His son, Sir Thomas Gorges, became captain in turn, and in 1593 he reported that the castle's gun platforms were in serious need of repair.
17th century
thumb|upright=1.2|Depiction of the 18th-century castle
In the early 1600s, England was at peace with France and Spain, and the country's coastal defences received little attention. The Gorges family continued as captains at Hurst, with Sir Edward Gorges taking up the post in 1610, but the castle was neglected. In 1628, the castle was unable to prevent Flemish ships from passing along the Solent, as only four or five of the castle's twenty-seven guns were functional, and the fort had no ammunition or powder for them. The government replaced all the brass ordnance in the castle, which were preferred, particularly on ships, as they could fire faster and more safely, with iron guns in 1635.
At the beginning of the English Civil War in 1642 between the supporters of Charles I and Parliament, the castle was occupied by Captain Richard Swanley, a supporter of Parliament.
18th century
thumb|upright=1.2|Hurst Castle in 1840, with the Hurst Tower (centre) and High Lighthouse (right)
Hurst Castle continued to be used as a military base in the 18th century, but was also used to hold a Franciscan confessor, Father Paul Atkinson. Amid concerns over the moral condition of England and a perceived threat to the established Church, an act for "further preventing the growth of popery" was passed in 1700; Hurst was chosen by the Privy Council to house any priests convicted under this law. Atkinson was probably the only person detained in this way, and he was held for 29 years from 1700 onwards, before finally dying at the castle.
There had been reported problems with smuggling around Hurst Castle since the 1670s, and these continued into the 18th century. In 1729, the Revenue service hired the Hurst, a wide, heavy yacht, to assist in anti-smuggling operations out of Southampton, arming its crew with muskets, pistols and swords. The problems persisted and, later in the century, the site was used as a rendezvous for smugglers led by a notorious criminal called John Streeter.
The castle fell into neglect, and reports from the 1770s through into the early 1790s noted extensive problems, complaining that the fort's guns could no longer be mounted on the dilapidated bastions and that water was seeping through the decaying walls. By 1793, the castle was considered to be "in the worst condition" of all the forts along the coast, and all its guns were unusable. Repairs were authorised, but little was actually done.
The Revolutionary War with France broke out in 1793, leading to the extensive modernisation of the castle. Repairs were carried out in 1794 at a cost of £647, followed by a review of the defences the next year by the Master-General of the Ordnance. The 16th-century castle was still strongly fortified by the standards of the time, but it could not support the heavier guns or batteries of artillery required to tackle enemy warships. Instead, two new gun batteries, each armed with five 36-pounder (16.3 kg) guns, were built alongside the castle in 1795, with a further eighteen 9-pounder (4 kg) guns mounted in the old fort; the guns concerned had all been captured from the French.
19th century
1800–58
thumb|Hurst Castle, depicted in 1862, showing the new eastern gun battery (right) and redesigned 16th-century fortifications
In 1803, war with France appeared imminent once again. After some discussions, it was agreed to adapt the 16th-century keep to enable it to hold six 24-pounder (10.8 kg) guns; the roof was vaulted and a central stone pillar was installed to run up through the building, work estimated at the time to be likely to cost £4,122. The historian Andrew Saunders likens the resulting building to the various Martello towers being constructed along the south coast at this time. It was proposed to build two temporary gun batteries to replace the 1795 emplacements, which had suffered from the salt air and decayed, but the plan was turned down in order to focus attention on the redevelopment of the keep. The work was carried out by a mixture of soldiers and civilian contractors and was completed by the end of 1806.
The remodelled castle did not play an active part in the Napoleonic Wars, although it was used in 1809 as a hospital for injured soldiers returning from the Peninsular War in Spain. A second lighthouse, known as the High Lighthouse, was constructed alongside the castle in 1812.
Official interest in Hurst Castle increased again in the 1840s, as the introduction of shell guns and steam ships created a new risk that the French might successfully attack along the south coast. Previously, sailing ships had been only able to pass the castle slowly when moving against the tide, making them vulnerable to its guns; steamships threatened to cruise past at speed. Military estimates and surveys in 1850 and 1851 suggested that the armament should therefore be significantly increased, to include more and much heavier guns.
Improvements were carried out between 1852 and 1856 at a cost of over £6,725. The keep was adapted to support 32-pounder (14.5 kg) guns, the seaward-facing bastions and curtain walls were reinforced with brick casemates and new gun positions, and the moat was deepened to protect against any surprise attack. Two batteries were built to the west and east of the castle, protected by shingle and earth and linked to the old castle by covered passageways called caponiers; a defensible barrack block was built beside the western battery, to provide further protection against any attack from the land. The result was that Hurst was re-established as a powerful fortification, equipped with fourteen 32-pounder guns, fifteen 8-inch (203 mm) shell guns and two 32-pounder carronades; in wartime, these required a team of 440 men, with a peacetime garrison of 105 soldiers. Fort Albert was built across the water on the Isle of Wight to provide supporting fire.
The 1852, the Isle of Wight Electric Company laid a specially-armoured telegraph cable to link the castle with Keyhaven on the mainland and Sconce Point on the island; two years later, the Electric Telegraph Company linked the castle to Southampton. Hurst used flags to pass on telegraphic messages to and from shipping entering the Solent. The introduction of rifled breech-loading guns, capable of firing explosive shells, and the construction of armour-plated warships left Hurst's guns and fortifications inadequate.
Hurst was equipped with new heavy, RML guns in heavily protected casemated positions. These weapons were slow to reload, so to ensure that the castle would have a good chance of hitting enemy ships passing at speed, two long batteries of weapons were built onto either side of the old castle, a west wing with 37 gun positions and an east wing with 24 positions. As work progressed, the decision was taken to reinforce the batteries with additional iron shields.
The work eventually cost £211,000; it began in 1861, with the majority of the work being completed by 1870 and the additional iron shielding by 1874. In peacetime, the castle held around 131 officers and men but it would have needed to be substantially reinforced during wartime if all the weapons were to be manned. Although the fort never received its full complement of guns, by 1881 it had ten 12.5 inch, 38 ton (317 mm, 39,000 kg) rifled muzzle-loading (RML) guns, fifteen 10 inch, 18 ton (254 mm, 18,000 kg) RML guns, five 9 inch, 12 ton (228 mm, 12,000 kg) RML guns, and 3 64-pounders (29 kg), together forming a powerful arsenal.
Two new lighthouses were constructed in the 1860s. The first was the "Low Light" built into the rear wall of the west wing of the castle.
By the 1880s and 1890s, both the power of naval artillery and the speed of warships had further increased, leading to further investment in the castle between 1888 and 1893. The keep's magazine, which could hold up to 2,250 shells, was reinforced with concrete and the south bastion of the old castle was filled in with shingle and concrete for additional protection. New 6-pounder (2.7 kg) quick-firing guns were installed in a battery on the end of the east wing, supported by machine guns, to enable them to target fast moving vessels, particularly the new torpedo boats. Further emplacements for 12-pounder (5.4 kg) guns followed, including one on the top of the keep.
Thomas Clarke, one of the executed leaders of the Easter Rising in Dublin in 1916, was born in Hurst Castle.
20th and 21st centuries
thumb|The theatre in the West Wing, with surviving original wall paintings from the [[Second World War]]
By the First World War, the guns installed at Hurst Castle in the 1870s were obsolete. The castle retained seventeen of them, as historian Coad states, wired up together "like a collection of elderly blunderbusses", but the fort depended on its newer quick-firing weapons.