There was already a small Saxon religious building made of wood here which William and Gundrada de Warenne rebuilt in stone. The first monks, under Prior Lanzo, extended it as an impressive church. The walls were decorated with beautiful frescoes and the floors covered with fine glazed tiles. While this first monastic church was being used the Great Church was under construction. Building took many years and once it was completed the First Church may have been used as the Infirmary Chapel.