Portchester Castle is a well-preserved example of a mainly Roman fortification, which lies on the northern shore of Portsmouth Harbour, approximately 6 miles north west of Portsmouth city itself on the southern English coast. Though in modern times this is a relatively urban area, the fortification is the oldest building in the region, and formed the traditional hub around which the village of Portchester and surrounding area were built.

The castle in its most recent form consists of an outer bailey with gates and bastions, and an inner bailey with a moat and gatehouse, palace, tower and keep. The site was originally a simple Roman fortification, though the castle was added to in phases during the Saxon and Medieval periods, and also in the seventeenth century. The original buildings have been extended many times to provide the castle that we see today.

The castle was initially constructed for defence purposes, however it has been used for many different purposes in its 1700-year history. It has been suggested that the castle was never “entirely abandoned after the collapse of the Roman Empire” (Goodall, 2006, p.29), though this suggests that there was a significant decline in the use of the castle as a fortification during this time. The castle was used again as a fortification by the Normans, and in later periods as a royal residence, and a prison after 1665.

The Thistlethwaite family, who still own part of the nearby Southwick estate, privately owned the castle from the mid 1600’s until 1984 (during which time it was seized and used as a prison by the army), however today the castle is run by English Heritage and is open as a tourist attraction and a common ground for local residents.

- The Watergate from inside the Outer Bailey. (Click to Enlarge). - Today, the English Heritage flag flies high above the top of the keep. (Click to Enlarge). - The Eastern Wall, looking north. (Click to Enlarge).


The initial date of construction is not entirely certain, though it is widely agreed that construction took place in the latter part of the 3rd century AD. Goodall suggests a date of “between AD285 and AD290” (2006, p.25), and Cunliffe adds that there is evidence of a smaller settlement in this area before the castle, with artefacts dating back to “the middle years of the first century, A.D.” (1975, p.9), though this was more of a “temporary settlement”, making the castle the first major development in this area at the time.


Initially called ‘Portus Adurni’ by the Romans, the castle came to receive its current name in around 501AD. As Barron explains, “Port, a Saxon warrior, captured the castle from the British and hence gave his name to the castle (Portcestre).” (1985, p. 36). Over time the spelling of this word has changed, and it wasn’t until the late 1800’s that the spelling ‘Portchester’ was officially adopted (a sign within the castle grounds spells it ‘Porchester’). Another traditional name is also used, ‘Caer Peris’, which is associated with a Saxon legend of pre-Roman occupation, though this has not as yet been confirmed. [N]

- Adaptation from Saxton's 1575 Map.
Portchester characterised by Castle.
(Click to Enlarge).
- Adaptation from Collins' 1693 Map.
Note the absence of the village itself.
(Click to Enlarge).
- Adaptation from Sheringham's 1840-1850 Mapping. Portchester village finally seen as a separate entity. (Click to Enlarge).

- A diagram to show the different ages of construction of the various buildings within the castle.
(Own Work).

Please Click the image to Enlarge