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.