Porchester Castle

Portchester Castle
Portchester, Hampshire
Portchester Castle, view of the inner bailey
Portchester Castle
Coordinates	50°50′12″N 1°06′47″W / 50.836546°N 1.113034°W / 50.836546; -1.113034Coordinates: 50°50′12″N 1°06′47″W / 50.836546°N 1.113034°W / 50.836546; -1.113034 grid reference SU624045

Portchester Castle is a medieval castle built within a former Roman fort at Portchester to the east of Fareham in the English county of Hampshire. It is located at the northern end of Portsmouth Harbour. Probably founded in the late 11th century, Portchester was a baronial castle taken under royal control in 1154. The monarchy controlled the castle for several centuries and it was a favoured hunting lodge of King John. It was besieged and captured by the French in 1216 before permanently returning to English control shortly thereafter.

Occupying a commanding position at the head of Portsmouth Harbour, in the medieval period Portchester was an important port. The castle saw the disembarkation for several campaigns to France led by England's kings. In anticipation of a French invasion during the first quarter of the 14th century, Edward II spent £1,100 repairing and reinforcing Portchester Castle. A plot to overthrow Henry V was discovered and the culprits apprehended at Portchester; this event features in Shakespeare's play, Henry V. Later in its history, the castle was used as a prison.

Today Portchester Castle is a Scheduled Ancient Monument, and a Grade I listed building. The castle has been in the ownership of the Southwick Estate since the 17th century but is managed by English Heritage and open to visitors throughout the year. The Norman church, St. Mary's, which stands in the south-east corner of the grounds, falls within the Anglican Diocese of Portsmouth.

The strategic importance of Portchester has been recognised since at least the 3rd century when a Roman fort was established on the site of the later castle. Though it is uncertain exactly when the fort was constructed, it is thought that it was built by Marcus Aurelius Carausius on the instructions of emperor Diocletian between 285 and 290. It was one of several forts built along the British coast in the period to combat raids by pirates. Portchester was probably a base from which the Classis Britannica, the Roman fleet defending Britain, operated. It is the best preserved Roman fort north of the Alps. Although the Roman army retreated from Britain in the early 5th century, it is unlikely that the fort was ever completely abandoned, although its use continued on a much smaller scale. A 10th-century hall and tower were discovered within the fort, suggesting it was a high-status residence during the Saxon period. In 904, Portchester came into the possession of King Edward the Elder and the fort became a burh to help defend the country against Vikings.