Portsmouth Harbour was used by the Romans as a safe port to conduct trade with the rest of their Empire. The first threat came from Saxon pirates, which led the Romans to construct a series of coastal forts known as “The Forts of Saxon Shore”. In 275 AD, a fortress was built in Portsmouth, the Portus Adurni.
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| The Forts of Saxon Shore |
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| Portus Adurni |
After the Romans departed from Britain in early 5th century, the fort at Porchester remained in use for the over 800 years before the next major development . In 1066 the Normans invaded Britain and began to dominate their newly acquired lands with castles
At Porchester the Normans retained the Roman outer walls, strengthening the defences by the building of an inner wall and castle keep. The defence in depth being a feature of future fortification and castle design.
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| Porchester Castle - medieval period |
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| Porchester Castle - medieval castle keep |
By the 15th century, gunpowder was beginning to shape the future of warfare. The initial weapons were made from wrought iron strips held together by rings to form a barrel. These would be replaced later by cast iron or cast bronze guns.
One effect of the emerging weapons technology can be seen with Portsmouth’s Round Tower, the first fortification to protect the entrance to Portsmouth Harbour. Built between 1418 and 1426, the rounded towers were better able to withstand bombardment than the old medieval castles.
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| Portsmouth Round Fort |
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| Portsmouth Round Fort / Victoria Pier |
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| Portsmouth Round Fort - seaward |
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| Portsmouth Round Fort - landward |
The other development was bastions. They provided enfilading fire, the aim being to bombard any would be attacker trying to scale the walls. In Portsmouth the fortifications were built to defend the town and the port.
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| Portsmouth Bastions |
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| Portsmouth - bastion |
To protect newly developing trade routes and the vital English Channel links, Henry began to build a fleet of ships. This included the Mary Rose, the Peter Pomegranate and the Sovereign, the three most powerful ships in the world at that time. The Mary Rose became flagship of the King's Fleet.
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| Mary Rose |
Henry’s Navy expanded to over 50 ships and is often viewed as being the foundation of the Royal Navy. The expansion of the navy also saw a reshaping of maritime warfare. The English Navy’s emphasis changed from close engagement and boarding, to ships carrying manoeuvrable guns capable of being quickly reloaded to produce a high rate of fire, engaging the enemy from a distance.
It was during Henry’s reign that the four wheeled carriage was developed that produced the manoeuvrability that gave the English Navy the advantage over their adversaries.
In 1534, Henry VIII broke away from the authority of the Roman Catholic Church in Rome and established himself as the head of the Church of England. The Pope demanded that Catholic monarchs of France and Spain remove Henry from power.
Henry fearful of invasion ordered that coastal areas be surveyed and mapped to identify possible landing sites. He issued a Device (legal authority) for the construction of coastal forts. He used the monies from the dissolution of the monasteries to fund his building programme, and brought the control of coastal artillery under Crown control away from local nobles.
The expanding navy and the fear of invasion meant Portsmouth developed as a place of strategic significance. Henry therefore built a series of forts to protect the Harbour and the passage past the Isle of Wight.
One Henry’s ‘Device Forts’ was Southsea Castle which was constructed in 1544. Like many of Henry’s forts it was a ‘star’ design with artillery platforms.
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| Southsea Castle |
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| Southsea Castle |
Henry VIII’s expanding fleet and coastal forts all required guns. Henry created the Office of Ordnance, its principal duties being to supply guns, ammunition, stores and equipment for the navy and coastal defences.
It was under Henry’s patronage that Peter Baude, a French gun-founding expert, discovered a method to improve the casting of guns in iron, technology that would be used until the mid 19th century.
Henry VIII created a strong navy and guns capable of defending England. A French attempt to capture Portsmouth in 1545 failed, as did the Spanish Amarda in 1588. Other incursions occurred, such as the Dutch raid on the Medway in 1667. Britain continued to invest and improve the Navy to defend the new trade routes of the British Empire.
That investment proved wise as a threat emerged at the beginning of the 19th century when Napoleon Bonaparte led his military to expand French territory and control in continental Europe. As part of his desire to look beyond Europe he clashed with Britain, and threatened invasion.
In order to achieve his aims, Napoleon needed to defeat the Royal Navy. The decisive battle took place on 21st October 1805 off Cape Trafalgar. Leading the British Fleet at Trafalgar was Admiral Lord Nelson, sailing from Portsmouth in his flagship HMS Victory.
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| Portsmouth Historic Dockyard |
HMS Victory (now preserved in the Portsmouth Historic Dockyard) was a three decked ship of the line carrying 104 guns of varying sizes. Ships of the time were usually triple or double decked equipped with smooth bore muzzle loading cannon.
It was the evolution of warship design over 300 years, which would continue for another 60 years. That change would occur in November 1859 when France launched the first ever ironclad warship, La Gloire.
This challenged the pre-eminence of the Royal Navy and was a major threat to British interests.The British response to this threat was the building of the Royal Navy’s first ironclad warship, HMS Warrior (now preserved in the Portsmouth Historic Dockyard) . HMS Warrior was a steam driven ship with sails as a back up. The single gun deck carried 40 guns.
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| HMS Warrior Portsmouth |
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| HMS Warrior - gun deck |
Whilst Britain and France has been allies during the Crimean War (1853-1856), tensions between the two nations increased after that conflict.
When the French supported Italy in a war against Austro-Hungry, fears grew that France was once again looking to exert military power. The launching of La Gloire and the strengthening of the naval base of Cherbourg convinced the Prime Minister Lord Palmerston that French Invasion was imminent
In 1860, Palmerston organised a Royal Commission on the Defence of the United Kingdom with a particular focus on the defence of the naval base in Portsmouth.
The report concluded that the existing defences had been rendered obsolete by advances in artillery technology. It also concluded that the Royal Navy was stretched on it’s home defence role, and as a consequence it was decided to build string land based defences to release the Navy for protecting the British Empire. A massive building program was instituted to upgrade land defences and build a series of coastal fortifications which became known as ‘Palmerston Forts’.
The threat identified to the Portsmouth Harbour and naval base was an invading force landing elsewhere along the coast, occupying Portsdown Hill, a ridgeline to the north of the harbour, from where the harbour and base could be bombarded.
A ring of forts around Portsmouth and also in the Solent were built between 1865 and 1880 at a cost of what would be now £70 million pounds.
Fort Nelson was one of a series of the forts built around Portsmouth. The forts were built as interlocking artillery planforms firing landward. Their function being to protect Portsmouth from attack from the land.
Fort Nelson is today preserved.
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| Fort Nelson |
It was also felt necessary to fortify the Isle of Wight and the entrance to Portsmouth Harbour.
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| Solent Forts |
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| Spitbank Fort |
By the time the Palmerston Forts were completed in 1880, they were obsolete, and have often been dubbed ‘Palmerston's Follies’. Advances in artillery meant that guns could be deployed at longer ranges making the forts of little importance.