Portchester castle is on the north side of Portsmouth harbour. Unusually, the Portchester site contains two castles - one within the other. Henry I built his castle in the 12th century inside the walls of a fort built by the Romans to protect the shore in Saxon times, towards the end of the third century AD.
The remaining Roman outer walls are about six metres high and up to three metres thick. They are said to be the best preserved walls of their type in northern Europe.
Also within the Roman walls is a twelfth-century church, St Mary's Parish Church.
St Mary's Church
This is now an active Anglican church but originally it was part of an Augustinian monastery founded around 1120. The church is the only building from the monastery that remains. For a detailed history of the church, see History of St Mary's Portchester.
The inner castle is known as the inner bailey. The buildings here were developed from the time of Henry I onwards. The buildings that can be seen today are:
- The Keep. This tower was built around 1130 as a place for important visitors, including royalty, to stay. It was extended in several stages, with floors being added until the fourteenth-century. Later, in the seventeenth-century, it was converted and used as a prison. As the tallest building in the area it would have enabled an enemy to be seen when still a long distance away. Go to the top of the keep for a fine view over the castle and its walls, and of Portsmouth Harbour beyond them.
- Palace of Richard II. Built in the late fourteenth-century as a residence for important visitors including the king himself.
- Great Tower. This was built by the Constable of the castle, Sir Robert Assheton in 1376 and was later repaired in the time of Richard II.
- Gatehouse. This is the gateway to the inner bailey and provided a bridge over the moat between the inner bailey and the outer bailey (previously the Roman fort). It was built in the twelfth-century, extended in the fourteenth-century and again in the seventeenth-century.
Visiting Portchester Castle
The castle is run by English Heritage. For opening times and prices, see English Heritage Prices & Opening Times for Portchester Castle.