Carisbrooke Castle

Carisbrooke Castle lies in the centre of the Isle of Wight in a strong defensive position on high ground. It is likely that it is on the site of a Roman fort and a castle definately existed there in the dark ages. It was rebuilt as a motte and bailey castle of steep earthen banks crowned with wooden stockades after William the Conqueror invaded England in 1066.

View along the north curtain towards the keep.

The castle was held by Empress Matilda during the Anarchy but was captured by King Stephen in 1136. The 12th century also saw the castle protected by stone walls and towers, transforming it into a formidable stronghold. In 1293 Carisbrooke castle was sold to King Edward I and it has belonged to the crown ever since.

The medieval castle consisted of a large earth mound, roughly square in shape, which was enclosed by stone walls. There were various domestic buildings and a well within the enclosure. In the north-east corner of the castle there was a tall mound (or motte) on top of which was the stone keep. Originally, the fortifications also enclosed an area to the east of the keep, the eastern bailey, but when the stone walls were built, this part of the castle was not included.

It was said that whoever held Carisbrooke Castle controlled the Isle of Wight, since its strength and central position are key to the strategic defence of the island. It is the only surviving medieval castle on the island.

Artist's impression of Carisbrooke Castle in 1600, with Genebelli's bastioned trace complete. View from the south.

When the French invaded the island in 1377, they failed to capture it and were forced to withdraw. In the 15th century the main gatehouse, in the west, was rebuilt by Lord Scales, who was the lord of the castle at the time.

The outer gate, built at the end of the 16th century, with the inner 15th century gate in the background.

As artillery developed into a powerful siege weapon, the castle's defences became obselete. The fortifications were not updated because England was not threatened with invasion for many years, until French troops landed on the island in 1545.

Although the French forces were defeated at the Battle of Bonchurch and did not get as far as Carisbrooke, the threat to the island highlighted the lack of modern defences. At the time no work was carried out at Carisbrooke, but Henry VIII'had an artillery fort built at Yarmouth in 1547.

In 1588 the Spanish Armada threatened England with invasion once more. In 1587 the defences were hastily strengthened in anticipation of an attack; the medieval walls were repaired and a ditch'was dug around the outside of the castle.

Cannon on the south-east corner of the eastern bailey. This earthwork platform may first have been constructed in 1587 in preparation for the coming Spanish Armada.

These preparations may have included the construction of the earthwork artillery platforms at the north-east and south-east corners of the eastern bailey (the earthworks that extended to the east of the stone castle). These platforms do not have the flanking capacity of the later bastions, so they may have been put up in 1587 in an attempt to bring the defences up to date.

The south-west bastion of Genebelli's new fortifications, seen from the castle walls. Originally, there would have been two levels of guns in the flank of the bastion.

In the event, the Spanish Armada came close to the Isle of Wight, but was driven away and eventually defeated so that no troops were landed on English soil, but the enemy had come close enough to provoke a rethink of the island's defences.

Sir George Carey, who was charged with the defence of the Isle of Wight and had ordered the Armada preparations, decided that more permanent improvements were needed at Carisbrooke Castle. He commissioned the Italian engineer Frederico Genebelli'(who was in the service of Queen Elizabeth I) to produce a design for strengthening the castle.

Genebelli designed a new outer trace of bastions enclosing the medieval castle and the old eastern bailey. These modern fortifications were a complete contrast to the medieval castle above, which had tall, thin, exposed walls.

View along the east curtain wall, taken from the south-east bastion looking north.

The walls of the new artillery fortifications were as low as possible and backed with ramparts of earth to strengthen them against cannon fire. There was a dry ditch in front of the fortifications to hide the base of the wall.

The recessed left flank of the south-west bastion.

Cannon in the flanks of the bastions could fire along the adjacent curtain walls and the faces of the neighbouring bastions, eliminating any dead ground in front of the walls. As a result, most of the defending artillery was sited in the bastion flanks.

Genebelli came to Carisbrooke in 1597 and drew up a plan for the fortifications. There were to be five bastions, forming a long pentagon with two bastions on the corners of the eastern bailey and three on the western end.

The fortifications are strongest on the south and east sides, where the ground is less steep and the danger of attack is greatest. The bastions covering these vulnerable sections are arrow-headed bastions'that originally had two tiers of guns in their flanks. This extra firepower is designed to offest the weakness of the gently sloping approaches to the south and east, and is not present on the bastion flanks that face along the north and west sides of the defences.

Labelled photograph of a model of Carisbrooke castle, the western end is in the foreground.

That Genebelli considered the north side of the castle to be less vulnerable to attack is evidenced by the lack of recessed bastion flanks here and by the fact that the north-west bastion is less than half the size of the others.

The small north-west bastion seen from the drawbridge. The incline the fortifications go up at this point is evident from the wall on the right.

Another oddity is the way that the trace does not follow the contours of the hill in the west, with the result that the bastion at the west corner of the defences is considerably higher than its neighbours, the north-west and south-west bastions.

This means that an attacker on the counterscarp (outer edge of the ditch) in front of the west bastion would actually be able to look down on (and hence fire into) the bastions either side. It is a mystery why Genebelli did not design the trace such that the west bastion was farther to the west. This would have meant that it would have been at the same height as the other bastions and would have had the added benefit of increasing the length of the curtain walls either side, which are rather short.

Perhaps such an extended trace would have been too expensive and it must be remembered that Genebelli was trying to force his trace to fit round the elongated rectangle of the medieval castle and the eastern bailey, so he could not choose his ground.

View from the south-west bastion, with the west bastion on the left. Again the disparity of height is notable. The gatehouse to the medieval castle can be seen on the right.

On the north side of the castle where the ground slopes away sharply, there was no room to build a bastion mid-way along the long south curtain, so Genebelli put an indented flank halfway along in order to provide flanking cover for the north face of the north-east bastion.

View along the north curtain from the north-east bastion. The indented flank and the flank of the north-east bastion can be seen in the centre of the picture.

Evidently the north-west bastion was not considered vulnerable enough to need any further covering fire than what was provided (albeit at long range) by the north-east bastion at the other end of the north curtain. Since the northern approach to the castle is so steep, this is not a weakness.

The entrance to the new fortifications is a gateway in the curtain between the west bastion and the north-west bastion. It is accessed via a bridge over the ditch and a path leads up to the main gate to the medieval castle, which is just inside.

In addition to the bastions around the outside, Genebelli rebuilt the south-west and south-east corner towers of the castle itself as small bastion-shaped towers. In reality, they were not designed to flank the castle walls but to serve as cavaliers, or elevated gun platforms.

The new south-west tower of the castle, which functioned as a cavalier, providing an elevated platform for the defenders' artillery.

Effectively, they existed in order to allow the defenders to make use of the height of the castle walls by placing artillery there. The guns in these cavalier-like towers would have a greater range than those in the bastions below, but they would be more vulnerable to enemy fire.

Looking out from the south-west cavalier-tower, it is obvious what an advantage it was to have artillery at this height. The south-east bastion can be seen in the distance.

Genebelli first visited Carisbrooke Castle in 1597. Work on the fortifications began shortly after his visit and was mostly finished by 1600. This was an impressively short construction time, although the cavalier-towers were not complete until 1602.

The new fortifications cost 4,000, which is equivalent to roughly 2,000,000 in today's money. This was a huge sum, although it was by no means unprecedented. Some years earlier, 250,000 (125,000,000 in today's money) had been spent on the new bastioned fortifications at Berwick-upon-Tweed.

Genebelli's design may not have been perfect, but it brought the defences into the age of artillery. Carisbrooke Castle was never attacked again, so the new fortifications were never put to the test, but they would have presented a significant obstacle to an invader.

View along the north curtain, with the north-east bastion in the foreground.

In 1636, the governor of the island reported that the castle was in a bad state. This may refer to the upkeep of the walls or it may be a criticism of the design, which was becoming dated by this time, since there were no outworks. In the end no improvements were carried out. The castle was made famous as being the prison of King Charles I, during the civil war, before his execution. It was home to the governors of the Isle of Wight until the Second World War, and was garrisoned until the mid 19th century.

Visiting Carisbrooke Castle

The keep seen from one of the artillery platforms in the eastern bailey, with a 24-pounder gun in the foreground.

Today Carisbrooke Castle is owned by English Heritage and can be visited most days (entrance fee 4.20). There is alot to see, with most of the medieval walls and the keep intact, as well as the 16th century bastioned trace and the Isle of Wight Museum.

The bastioned fortifications are almost intact, although the tiered gun emplacements in the flanks of the arrow-headed bastions have not been kept up, and seem to have been altered at some point. That said, Carisbrooke Castle presents a rare example of an early bastioned trace in England. It is just over a mile away from Newport, one of the biggest towns on the island, which is served regularly by buses from all the ferry ports.

Condition Access to fortifications Size of fortress Accessability of town Museum/Info Overall score
9 10 7 8 7 8.2
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