Origins The Priory was founded in the reign of Henry I, about 1123 by Robert de Haia (or de la Haye), Lord of
Halnacre by gift of the king. A Saxon church had existed on the site before the Conquest. The Priory was founded for three
Benedictine monks, and was a dependency by the
Lessay Abbey in Normandy. In about 1126, upon the marriage of Robert's daughter Cecily to Roger St John the number of monks living at Boxgrove was increased from the original three to six. Robert had died by 1165. By 1187 there were 15 monks. A 19th monk was added to the priory in about 1230 by William de Kainesham,
Canon of
Chichester. By 1535 the priory's possessions were worth £185 19s. 8d. gross, and £145 10s. 2½d. clear.
Dissolution The
Priory was
dissolved in 1536. At the time of the dissolution there were eight priests and one novice, as well as twenty-eight servants and eight children living in the priory. After the dissolution, the Priory church became the parish church. ==Modern history==