The Church of St. Mary was built by the Normans within the walls of Portchester Castle in the 1120s. It was gifted to Augustinian canons by Henry I. The building was badly damaged by fire caused by Dutch prisoners of war in 1653, but later repaired. It remains in use as a church to this day.

Amongst the numerous graves in the cemetery is one belonging to that of Thomas Goble. He was a veteran of the Battle of Trafalgar, serving as a Master's Mate aboard Nelson's flagship, HMS Victory.