Soon after the Norman Conquest, the church of St. Olave, with four acres adjoining, was given by the Earl of Richmond to Stephen of Whitby to found a Benedictine monastery. The site, however, was church property, and the Archbishop only relinquished it when William II gave him an equivalent. King Rufus laid the foundation stone of the abbey church, which was dedicated to St. Mary. The foundations of the eastern part of this church have been laid bare and show the apsidal terminations. The introduction into England of the Cistercian order, with their stricter rule of conduct, led some of the monks of St. Mary’s to attempt a raising of the standard of discipline in their own monastery. The other monks, however, resented their interference. The reformers, filled with admiration of the accounts they heard of the holy lives led by the inmates of the Cistercian house of Rievaulx, were now anxious to found a colony of that order and communicated their desire to the Abbot of St. Mary’s, who, however, refused to allow them to leave, as it would bring discredit on his abbey. The reformers included the prior, sub-prior, sacrist, almoner, and precentor. The prior consulted the Archbishop, who decided to hold a visitation at the abbey. Archbishop Thurstan on the day appointed rode to the abbey gatehouse attended by the Archdeacon of York, the Minster Treasurer (afterwards St. William), the Prior of Guisborough, and the Master of St. Leonard’s Hospital. Leaving their horses at the gateway, they walked to the chapter house and were received by the abbot, who protested against anyone entering but the Archbishop and his clerks. The Archbishop remonstrated, but the monks who had filled the chapter house, considering it was a Cistercian attack on their own order, created an uproar by hooting and screaming and prevented the Archbishop being heard; he, however, in a lull shouted, “I place the Abbey under an interdict.” “Interdict it for a hundred years,” exclaimed one of the monks, and then arose the cry of “Catch them!” The Archbishop with his retinue and the thirteen reformers were alarmed and took refuge in the church, and after a time were permitted to leave the abbey. The Archbishop befriended the outcasts and subsequently gave them a plot of ground, near his manor at Ripon, on which they founded the Cistercian Abbey of Fountains. Simon of Warwick became Abbot of St. Mary’s in 1259, and placed it in greater security from the attacks by the citizens, between whom and the monks were often quarrels, owing to the privileges claimed by the abbey. The monastery, being just outside the city, was always in danger from raiding expeditions of the Scots, so in the year 1266 the abbot had licence from the king to wall in the abbey close.