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The Round Tower
Broad Street, Old Portsmouth, Hampshire, PO1 2JE
The Round Tower and the other nearby fortifications were purchased by Portsmouth City Council the 1960s. The interior (ground floor) of the Round Tower is administered by Portsmouth City Council. In 2011 the interior of the Round Tower was converted for use as an exhibition gallery, and exhibitions are sometimes held there. The roof of the Round Tower is open to the public all year round.
For hundreds of years, Portsmouth’s importance as a naval base meant that it was one of the most heavily defended cities in Europe. The Round Tower was the first of a series of permanent fortifications that were built in Portsmouth over the centuries.
Work on the Round Tower was begun in about 1418, and it was completed in the 1420s. Before 1400, Portsmouth had been attacked and burnt several times by the French during the Hundred Years War. The Tower was intended to defend the entrance to the Harbour and prevent enemy ships from entering. It was not built specifically to defend the town.
At the time it was built, the Round Tower was actually outside the town walls, on the small peninsula known as Point. The nearest gate into Portsmouth – Point Gate, later known as King James’ Gate – was roughly halfway along Broad Street between the Round Tower and the nearby Square Tower (built 1494). The Dockyard as we know it did not exist, and the King’s ships were moored in The Camber, the small harbour that today is mainly used by fishing boats.
At first the Round Tower was known as “Master Ridley’s Tower”, after John Ridley who in 1536 had been put in charge of it and other royal buildings in the town. Like most fortifications, the Round Tower has been modified many times in its history.
In the reign of Queen Elizabeth I (1558-1603) it was rebuilt with six gun ports for cannons, three of which have since been filled in (to the left of the existing gun ports, as seen from inside the Tower). The Tower has always been at risk of being undermined by the sea. In the reign of Elizabeth I, all boats that regularly went back and forth between the Isle of Wight and Portsmouth had to deposit a boatload of stones around its base.
Photo above: members of the public looking at temporary displays during an open day inside the Round Tower. They are standing on a stone gun platform, which slopes to help absorb the recoil when a cannon was fired. On the far right of the photo it the Tower's central pillar.
The Tower was extended in height shortly before 1815, and again in 1850 to bring it to its present height of 35 ft (11 m). The interior of the Tower as seen today dates from the period of the Napoleonic Wars (before 1815) when the central column and brick vaulting were added to support the weight of guns on the roof. The stalactites growing from the ceiling are due to minerals being washed out of the mortar holding the bricks together.
As an additional defence, an iron chain could be stretched across the Harbour mouth from Capstan Square next to the Round Tower, over to the Gosport side, where a wooden tower was built at around the same time as the Round Tower. This chain boom was used for hundreds of years, with the chain being replaced at intervals, and a similar defence was even in place during the Second World War. Two original links from one of these chains can be seen in Southsea Castle (a replica link is also on display in Capstan Square).
Over the centuries, Portsmouth’s defences often fell into disrepair, only being repaired when there was a new invasion threat. When the Round Tower was first built, Portsmouth’s defences were mainly constructed from earth and timber. As guns grew more powerful, the Round Tower’s defences were not sufficient. In the 1680s, Eighteen Gun Battery was built next to it, stretching towards the Square Tower. This was part of a major revision of Portsmouth’s defences on the orders of King Charles II, carried out by the Dutch fortress engineer Bernard de Gomme. Around 1850, the whole area between the fortifications and Broad Street was walled off to become Point Battery and Barracks, providing living quarters for the soldiers who manned these guns. Today the outline of the soldiers’ barracks rooms is marked out with bricks on the ground.