History and Stories
The view across Portchester Castle from the keep

History and stories: Portchester Castle

Portchester Castle’s remarkable history begins in the 3rd century AD when the Romans built a vast fort here. In the 5th century this waterside fortress was transformed into a Saxon settlement, and after the Conquest of 1066 it became a Norman castle. For medieval kings it was an important embarkation point for crossing the Channel.

From 1665 Portchester served as a prisoner-of-war camp – a role that reached its height during the French Revolutionary and Napoleonic wars of 1793–1815, when it housed up to 8,000 prisoners, of many nationalities and backgrounds, at any one time.  

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The Norman keep of Portchester Castle

Key facts about Portchester Castle

  • Portchester’s commanding location within Portsmouth harbour has made it a major factor in the defence of the Solent for centuries.
  • Portchester is the best-preserved Roman fort in northern Europe – the only one whose entire defensive circuit survives little altered from when it was built.
  • After the Norman Conquest the Roman walls became the outer defences of a great castle, its main buildings set within one corner of the Roman fort. Surviving medieval buildings include the magnificent Norman keep and an impressive royal palace built in the 1390s for Richard II.
  • Medieval kings used Portchester to gather their forces before crossing the Channel – most famously, it was from here that in 1415 Henry V launched the invasion of France that culminated in his triumph at Agincourt.
  • Portchester’s role as a depot for prisoners of war saw it house 2,500 black and mixed-race prisoners from the Caribbean in 1796–7, as well as a group of French prisoners who set up a theatre in the keep in 1810.
Read the full history of the castle

Portchester’s Prisoners of war

More resources

  • Why does Portchester Castle matter?

    Discover the importance of Portchester’s buildings, from the exceptionally well preserved Roman fort to Richard II’s royal palace.

  • Description of Portchester Castle

    Read a description of the castle – the walls and towers of the Roman fort and the medieval buildings within it.

  • Research on Portchester Castle

    Find out how archaeology has informed our understanding of the castle, and what remains to be discovered by further research.

  • Sources for Portchester Castle

    Use this list of visual and written sources, published and unpublished, to learn more about Portchester Castle and its history.

  • Plan of Portchester Castle

    Download this PDF plan of Portchester to explore the castle and see how its buildings have developed over time.

  • Buy the guidebook

    This guidebook gives a vivid account of the castle’s extraordinary history and its occupants, as well as a full tour of the buildings.

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