Roman Fort Portus Adurni

Portchester's location made it a site in English military history for centuries. Even before the Roman conquest, a British stronghold called Caer Peris is said to have existed here, which was besieged and destroyed by the Romans in 43 AD. Around 285 AD, Admiral Carausius was tasked with clearing the English Channel of pirates, leading to the establishment of the Litus Saxonicum, or Saxon Shore. The fort of Portus Adurni was built in the late 3rd century AD under Carausius as a naval base and was later used by the Anglo-Saxons as a royal court. Following the Norman Conquest in 1086, construction of a castle began in the northeast corner of the fort. Portchester served as a launching point for campaigns into France during the Hundred Years' War and later housed troops during the Civil War and prisoners of war during conflicts against the Dutch and Napoleon.