An inscription on a mid-11th century sundial describes the rebuilding of the church at that time, stating that ‘Orm son of Gamal bought St. Gregory’s MinsterMinster Originally a church with a group of clergy which served a large area. Later used to describe a church staffed by many priests or a monastic community when it was utterly ruined and collapsed and he had it rebuilt from the foundations to Christ and St. Gregory’. This indicates the previous existence of a monasteryMonastery The house of a religious community church dedicated to St Gregory the Great, the popePope Head of the medieval church in the West. Used as a title preceding the name of the Bishop of Rome, the head of the Roman Catholic Church who sent the missionMission 1. A group of people sent out to share religious faith. 2. The task of sharing faith. to convert the English to Christianity. Excavations have revealed some of the foundations of this earlier monastery and evidence for its destruction in the 10th century. Two high-status grave slabs date from the late 8th or early 9th century and show that this was a monastery of some importance. Other early sculpture includes a figure of the crucified Christ on a cross from the late 9th or early 10th century.
References: Grenville and Pevsner, The Buildings of England. Yorkshire: The North Riding, pp. 379-81.