Portchester Castle (known in Latin as Portus Adurni - 'port at the hill') is a Roman fort at the northern end of Portsmouth harbour. It was originally a square enclosure with each corner having a bastion¹. On each of the four sides between the corner bastions, there are another four evenly-spaced bastions. In the west wall in the centre is the main gate, and on the east side again in the centre is a smaller water gate. Both gates are exactly opposite each other. As for the internal layout, it was probably similar to Birdoswald fort on Hadrian's wall.

Today it is an almost complete Roman fort. Almost all of the walls are intact apart from the loss of six of its original 'D'-shaped bastions. The keep in the north-west corner has taken some of the wall and one corner bastion from the northern side. Also missing are two bastions from the western side, and two bastions from the eastern seaward side, and lastly the bastion on the south-west corner is missing. It has, however, been stripped of some of the more useful limestone.

The castle is still in such good condition both because it has been in continuous use since it was built, and because the Roman architects built it to last.

Saxon Shore Forts

The castle was built in the period 285 - 290 by Marcus Aurelius Carausius as part of the defensive system known today as the Saxon Shore Forts. The others Shore Forts are noted in a document of the Roman imperial archives: Notitia Dignitatum. They are listed as follows:

• Portus Adurni - Portchester Castle
• Anderida – Pevensey
• Portus Lemanis – Lympne
• Dubris – Dover
• Rutupiae – Richborough
• Regulbium – Reculver
• Othona – Bradwell-on-Sea
• Gariannonum – Burgh Castle
• Branodunum – Brancaster

There was also Walton fort in Dunwich, then known as Dummoc, which was situated at the mouths of the Rivers Orwell, Deben and Stour off Felixstowe. This fort was omitted from Notitia Dignitatum so no Latin name is listed; other Roman references give the size as 100 metres square, with walls of similar dimensions to those of Portchester. Modern lists omit the fort as it disappeared into the sea some time after 1600.

The Building

The walls of Portchester were built of flint and limestone, and enclosed an area of 36,489 square metres. The size of the castle is 200 metres square, and the walls are 6 metres high and 3.2 metres thick.

Some surveys of the site within the walls have revealed that there were several previously-unknown buildings and six wells dating from the Roman, Saxon and medieval periods that had been built within the walls of the castle.

The Castle is set on a north-south axis, but is about ten degrees off true north. The castle is in fact square, although it does not look it when viewed from the air. The extensively refurbished Roman gatehouse is built of stone, and has a pitched clay tiled roof, with two floors over a double arched entry way. This gate is set in the western wall and a path runs from west to east from the Roman gate to the Saxon (originally thought to be Norman) rebuilding of the Roman watergate on the eastern wall. This structure, which is sited exactly opposite the main gate had three floors, and has an internal stone spiral staircase.

The Priory

In the south-east corner there is a 12th-Century Augustinian priory chapel, now known as St Mary's, Portchester. It still has the original Norman west door, and a replacement roof from the Tudor period. The priory, which was built before the castle passed into royal hands, was constructed against the southern wall. It has now gone, but at its height there were a kitchen and refectory, a cloister, sleeping quarters and storage buildings. If you search for them, there are still some traces: the toilets set in the southern side of the Roman wall and a fireplace near the watergate.

The priory was built by the Augustinian canons (who wore black robes and black caps). It was one of just six Augustinian priories in England at this time. To support the house, there was a grant of land nearby with some woodland for timber. By 1155, the Augustinian canons had moved to the village of Southwick due to lack of space.

The Early History

In the 1st Century AD, Emperor Vespasian left here for the siege of Jerusalem. He had first conquered the Isle of Wight, Kent, Surrey Sussex and Hampshire. The next mention is of St Paul, who is said to have landed at or near Portchester, and preached by a grove of trees nearby. The grove was later given the name Paulsgrove in memory of the saint's visit.

In the 5th Century, when the Romans withdrew from Britain, the island fell victim to invasions of Angles, Saxons and Jutes from Northern Europe. These Anglo-Saxons, as they came to be known, made the castle a part of their defensive system of Wessex. There is some evidence too that it was at this time a trading centre, due to the coastal location of the castle.

There is an Arthurian connection with Portchester. In the Black Book of Carmarthen there is a poem (in Welsh), with one verse that concerns Arthur and Portchester, as follows:

In 'Llongborth' I saw Arthur's,
Brave men who cut with steel,
The Emperor, ruler in toil of battle.

The connection is tenuous, but it has been worked out that the 'Llongborth' in the poem is Portchester. At one time, the castle was part of the kingdom of Dumnonnia ruled by a prince named Geraint. The word 'Llongborth' means warship port - the most fitting location in Geraint's kingdom was Portchester, and that is all there is.

Check out the Arthur website listed in the Referenced Sites section of the panel to the right for further details.

The Post-Conquest Expansion

After the Norman Invasion, the additions were begun. First came the Norman keep, started by William Maudit in 1086, who built it using stone imported from his French estates in Caen. During this period, Henry I used it as a stopping off point on his trips to France. By 1130, William Maudit had completed a two-storey keep, with an entry door four metres above ground level. This allowed for the wooden access stairway to be demolished to protect the door if the keep was attacked.

Another two stories were added later (there are two original windows on the main floor and a beautiful stone spiral staircase). This may have been too much for the foundations, as there is a large settlement crack on the north wall of the keep. In the medieval period, the inner bailey and a moat were added. This included a gate house, a 'constable's house', Ashton's tower, a full range of service buildings, the bailey moat and the exterior moat and ditch. Richard II's palace apartments were in the west range, with a great hall to the south.

Other frequent visitors to the castle at this time included the Monarch and the court. First was Henry II, who stayed on a few occasions and started to use the Keep as a treasury in 1163. It must have been an impressive castle as it was at Portchester that Henry II met the Bishop of Evreux, who came to intercede between Henry II and Thomas à Becket over the matter of the constitutions of Clarendon. After the murder of Thomas à Becket, Henry II met with the Papal Legates to announce he was innocent.

After his peace with France, Richard II made Portchester into a palace. After he came to the throne, King John often visited between 1207 and 1214, as his favourite castle at Odiham was a four-hour ride north of Portchester. Odiham was being built during this period, and one of the reasons for the visits may have been to view progress of Odiham on the ride down from London or Windsor. On 21 May, 1215, a French army landed at Stanhope and Sandwich and marched to London. One of the castles the French captured in 1215 was Portchester. The others included Odiham and Dover, and in this period Louis Dauphin of France, son of Louis XV, stayed at Portchester .

Henry III is known to have visited Portchester, and Edward III later used it as his headquarters in 1345 whilst preparing for the Battle of Crecy.

Sir Robert of Ashton was the constable of the castle during the period 1376 - 81, and was responsible for the tower in the north east corner of the bailey. Situated midway between two of the original 'D'-shaped Roman bastions, it would have been some nine metres above the wall and formed a corner and stair for a range of two-storey buildings extending from the western and southern sides. The next royal visitor was Henry V, who left from the castle for Agincourt in 1415. The Hundred Years War meant that the castle was kept fully prepared for war during this period. This was good planning as Portsmouth was burned, but the castle withstood a fierce attack.

The tower, known as Ashton's Tower, was an improvement in the defences as it provided a firing platform for the new black powder guns. The tower is equipped with gun loops, which are shaped like an inverted keyhole. On the top of the wall, projecting arches have been constructed making it harder for intruders to climb over the top. One of these enclosed a toilet for the garrison to keep them on duty while on the walls - waste fell through holes and passed outside the walls, and could give attackers an unpleasant surprise. In about 1500, a walkway on the top of the wall was built, which also had positions for hand-gunners.

The buildings of the bailey were altered and rebuilt at least three times, and by the 15th Century had become very luxurious by the standards of the time. The inner gatehouse and drawbridge were also extended, the last work being recorded in about 1638.

The Slow Run Down

Henry VIII and Anne Boleyn had a holiday at Portchester in 1535. It is from this period onwards that the castle started its decline. The fact was that Portsmouth and Gosport at the mouth of the harbour now held the key to the area's defence. Gunpowder now enabled the coastal forts to keep the harbour safe from attack, and in addition to his improvements to the Portsmouth defences Henry VIII added a new Castle at Southsea. Built in 1544, Southsea was the very latest in artillery forts and this along with other installations in the area made Portchester redundant.

Queen Elizabeth I was entertained here in 1601. It was one of her last tours of her realm as she died in March 1603. During this period, the Tudors had a storehouse in the castle, but this was relocated to Portsmouth as the city developed its military installations as ordered by Henry VIII. Charles I stayed at the castle frequently², but the castle was held for Parliament during the English civil war.

Later it was used as a prison for the Dutch after Blake's sea victories - these men were put to work, and the mast pond in Portsmouth dockyard is a result of their work. During the Napoleonic wars, the prisoner of war population was so large that after the civil prisons such as Dartmoor and Old Mill Prison, Plymouth were full about five thousand Frenchmen were imprisoned at Portchester, a distinction shared with Norman Cross, Peterborough, and numerous prison hulks around the coast. It is interesting to note that in 1780, over one hundred American Revolutionary War prisoners of war were also held at Forton prison near Gosport.

Until 1804, the castle was used as a hospital and barracks, but it was difficult to get to and the army moved out. The castle fell out of use as the fortifications of Gosport and Portsmouth developed even further.

The HMS Portchester Castle (K362), a Castle Class patrol vessel, was named after the Portchester. Launched June, 1943, she was in service until May, 1958.

Portchester Today

Today the castle is a tourist attraction, which is open to the public and free to enter. There is only a charge to enter the keep, but this is worth every penny as it contains an excellent museum. You can climb to the top of the tower and the view is fantastic, so remember to take a camera. The enclosed area within the walls is a wonderful place for a picnic, sheltered from the wind. Children will love it. Mind the moat, though - it is not deep, but very muddy.

As the road (Castle Street) approaches the gatehouse, you will pass through Portchester Village, a wonderful village of 18th-Century houses. As Castle Street passes through the gate it becomes Church Road, which makes this one of the few castles with a named road within its walls. Just before the gate there is a road to the left called Waterside Lane. This will give you a wonderful view of the keep and Roman walls on the northern side. Have your camera ready.

The castle is also used as an amenity by the local residents and has the village cricket pitch within its walls. English Heritage permits access to the castle for sponsored and historical events. The media also make use of the castle; the UK Channel 4's Time Team has visited, and it has been used as a setting for films and television productions.

The castle has a well-kept air and is a credit to the local council and English Heritage who care for it. In the words of English Heritage, 'Portchester can be considered a complete history of England in one place'.