For Christians, the approach of the first millennium sparked a revival in spirituality throughout Latin Christendom. Monasticism, according to the rule of St Benedict, was at the forefront of this process. In Scotland , the person frequently credited with introducing reformed monasticism is Margaret, queen of Máel Coluim mac Donnchada (Malcolm III). While there is little doubt that Margaret did found a new Benedictine priory at Dunfermline with monks from Canterbury , this initiative failed between 1093 and 1100 AD (though later revived by her sons). Consequently, scholars are still debating the exact effect Margaret had on the transformation of the Scottish church.
What is perhaps remarkable about Margaret was the devotion to reformed monasticism that she inspired in her sons, Edgar, Alexander and David mac Máel Coluim. It was during the reigns of these three kings, particularly David mac Máel Coluim (David I – 1124 to 1153 AD), that large-scale endowments were made to the Augustinian, Tironesian and Cistercian orders. The first foundation David made in Scotland before 1124 AD, as earl of Huntingdon, was at Selkirk – the community later moved to Kelso – with monks from Tiron, near Chartres . After 1124 AD, as king, David also founded the Augustinian houses of Holyrood, Jedburgh and Cambuskenneth, a community of Cluniacs on the Isle of May, a Benedictine foundation at Urquhart in Moray and three Cistercians abbeys: Melrose (1136 AD), Newbattle (1140 AD) and Kinloss (1150 AD). Both Newbattle and Kinloss were ‘daughter’ houses of Melrose , and Deer was founded by William Comyn, earl of Buchan, as a ‘daughter’ house of Kinloss c.1219 AD.
The link between these new orders of regular clergy and the reform of the Scottish episcopate is clear: a number of abbots were chosen as bishops in sees like Glasgow and St Andrews . David mac Máel Coluim, clearly concerned with the religious reform of Scotia , chose men renowned for their piety and simplicity to undertake a programme of diocesan reconstruction and to encourage the erection of a parochial structure with attendant churches served by secular priests. However, this revolutionary restructuring did not necessarily mean the end of the Celtic Church. There is clear evidence that at least one community of céili Dé (clients of God) secular priests survived, at least in name, at St Andrews until the fourteenth century. However, it is likely that the early Columban monastery at Deer did not survive beyond the foundation of the new Cistercian house. If it did, there is no record of it in primary sources.
Nevertheless, although the church in Scotland was re-organised during this period there was no archbishop who could exercise metropolitan status (superiority over the others). Until the end of the twelfth century, Scottish bishops (and kings) had to resist the claims of successive archbishops of York that they exercised metropolitan powers over the bishops of Scotland . However, in 1192 an agreement was reached – pronounced by Pope Celestine III in his bull Cum universi – whereby the diocese of Galloway would remain subservient to York and the remaining ten Scottish bishoprics became ‘special daughters’ of Rome, subject only to the papacy (the diocese of the Isles, as lands belonged to Norway, remained subject to Trondheim until c.1350 AD). By 1225 AD, Scottish bishops had also secured the right to hold a provincial council for self-government. Thus, by the beginning of the thirteenth century the medieval church in Scotland occupied a unique position in Latin Christendom.