Since Roman Times, there has been a castle at Portchester, which emphasises the importance of its rather scenic location, perfectly positioned for defending Portsmouth harbour and the Channel. Even today, the most complete Roman Walls in Europe, from the 3rd century fort, can still be found on this site. The curtain wall of the Outer Bailey originally had twenty bastions and four gates - two of these massive gates are known as the Watergate and the Landgate - and the south wall displays some of the best examples of Roman work.
The Norman Castle was built in one corner of the Roman fort and, throughout medieval times, the main part of Portchester Castle would have been the Inner Bailey, which contained the living apartments of the royal palace and the Constable's residence. In the 13th and 14th centuries, the ranges of buildings on all four sides of the Inner Bailey, were rebuilt several times. Controlling the drawbridge over the moat was the Gatehouse, and this was extended forward several times between the 12th and 17th centuries. On the outside of the Gatehouse, can be seen the partly ruined roundels, which were large enough for a man to stand on.
In the north-west corner of the Inner Bailey stands the 12th century Keep, the only building in this area not to have been successively rebuilt. Built across the Roman wall in two phases, it may have doubled in height, and a succession of rooflines can be seen where earlier pitched roofs have been replaced with later lead ones. A series of forebuildings protected entry to the Keep, and housed the Castle Chapel, of which very little is in evidence today. Fortunately, the arms of Henry VII survive below the window in the south wall. As in other areas of the Keep, there are traces of painted decoration in the present Exhibition room, created by prisoners of war who were retained at Portchester Castle in the 18th and 19th centuries. Some of the paintings relate to theatrical performances.
Ashton's Tower, found in the north east corner, was named after the constable of the castle, Sir Robert of Ashton (1376-81). Not only did the Tower provide an extension to the constable's living quarters, but it also strengthened the defences of the Inner Bailey. At this time there were new hand-held guns, and the keyhole-shaped gun-loops were introduced specifically for them. Around 1390, the parapet walk was constructed, also with gun-ports, and much of this can still be seen today. At each end of the parapet a projecting arch (squinch) was built to make it difficult for the walls to be climbed. An external latrine, built on one particular squinch, was also an added incentive to leave that area of wall well alone.
Being located near the Channel, many Royals favoured its convenience and its buildings reflect that. Henry I found its position fortuitous when travelling to France, and in 1163-4 when bullion was being shipped to Normandy, Henry II made several visits to Portchester Castle. During the 14th century, Portchester Castle was well maintained for fear of constant threats from France throughout The Hundred Year War, and at the end of the century, when a temporary state of peace existed, Richard II transformed the inner courtyard buildings into a Royal Palace. In the 17th century, Sir Thomas Cornwallis was responsible for much rebuilding in order to provide more spacious accommodation, and in 1601 Queen Elizabeth I was entertained at Portchester Castle.
This site, covering some nine acres in total, provides such a wealth of fascination, not only because its history spans some 2000 years, but there is so much evidence of all periods of occupation - from Roman fort to medieval stronghold to Royal Palace to Prison. A small Norman church with a beautiful west front, has also survived on the site.