Great Grandson - Portchester Castle - Near near Port Solent, City of Portsmouth, Hampshire, England
The first fortification on the site was a Roman Fort dating back to 285 AD.
From the mid 1600's Portchester Castle was owned by the Thistlethwaite family who only ever lost control over it for a short time when it was seized by the army for use as a prison. The family owned the castle until 1984 when it was handed over to English Heritage.