Yet the development of a national system of parishes was not a creation out o nothing; it was rather the most obvious aspect in David's reign of a shift from existing but piecemeal developments into a systematic effort of royal policy. The law or 'assize' of David I which made compulsory the exaction of the teind (or tithe) from,.ill who lived in the area served by a parish church was the vital, practical legal step and it rightly gives to David the accolade of founder of a system of parishes which remained virtually unchanged until the nineteenth century. Grants of lands in feudal terms often coincided, in David's reign and after, with the effective creation of new parishes. In Moray, the spread of a parish system was one of the instruments of the feudal colonisation of a troublesome province. Yet in other parts of Scotia the new parishes seem often to have been fitted into old boundaries. The huge diocese of St Andrews which stretched both north and south of the Forth shows that the emergence of a parish system was not a tidal wave carrying all before it: in Lothian and the Merse there are indeed many examples, such as the parish kirk at Ednam, of 'feudal churches' linked to new Anglo-Norman proprietors; but in Fife and especially north of the Tay in Angus and the Meams, where the erection of parish churches generally predated feudal settlement, there was a closer correspondence between existing sites or places linked to saints' dedications and the new kirks.

The same shifting balance between Celtic survival and the new Church of the twelfth century lay behind the development - or reconfiguration - of dioceses. By 1155, there were ten dioceses. Of these, only three - Moray, Ross and Caithness were creations of the twelfth century, all significantly in the troubled north, the outlying province given special attention by David I and his successors. The remainder were all survivals of different kinds: Whithom corresponded to the old lordship of Galloway and was little different from the see established by the Northumbrian Church in the seventh century; Glasgow, the see of St Mungo, stretched as far south as had the old kingdom of Strathclyde; and the bewildering complexity of the boundaries of the others, with detached portions speckling the map, is testimony to their origins as paruchiae of mother churches of a Celtic type. The lands and parishes of the diocese of Dunkeld spotted the map from Argyll to Berwickshire. Neither the diocesan system nor the bishops who ran it in the twelfth century were so very different from the sees and churchmen of the eleventh. There were bishops with Norman names in David's Scotland, but there was no dramatic, sudden swamping of the secular clergy with outsiders, as happened in William I's England.