It is one of the relatively few surviving abbey churches of the medieval period, and, although not a cathedral, is one of the biggest. It was founded by Benedict of Auxerre in 1069 and subsequently built by the de Lacy family.
On 31 May 1256, the Abbey was bestowed with the grant of a Mitre by Pope Alexander IV and from this date was a “Mitred Abbey”. This privilege fell in abeyance a number of times, but on 11 April 1308, Archbishop William Greenfield confirmed the grant, and Selby remained a “Mitred Abbey” until the Dissolution of the Monasteries. Archbishop Walter Giffard visited the monastery in 1275 by commission, and several monks and the Abbot were charged with a list of faults including loose living, (many complaints referred to misconduct with married women). In 1279 Archbishop William de Wickwane made a visitation, and found fault with the Abbot as he did not observe the rule of St Benedict, was not singing mass, preaching or teaching, and seldom attending chapter. Things had not improved much in 1306 when Archbishop William Greenfield visited and similar visitations in later years resulted in similar findings.
The community rebuilt the choir in the early fourteenth century, but in 1340, a fire destroyed the Chapter House, Dormitory, Treasury and part of the church. The damage was repaired and the decorated windows in the south aisle of the Nave were installed. In 1380-1 there was the abbot and twenty-five monks. In 1393 Pope Boniface IX granted an indulgence to pilgrims who contributed to the conservation of the chapel of the Holy Cross in the Abbey.
The fifteenth century saw more alterations to the Abbey. The perpendicular windows in the North Transept and at the west end of the nave were added and the Sedilia in the Sanctuary was added. One of the final additions was the Lathom Chapel, dedicated to St Catherine, east of the North Transept, in 1465.