Habitual masonry styles and the local organisation of church building in early medieval Ireland

The results of a masonry analysis of the majority of Irish pre-Romanesque churches are presented. A number of local styles are identified in high-density areas, mostly in the west of the country and it is shown that the differences between these styles were not determined by geology. It is argued that these styles represent habitual variation and are therefore indicative of local groups of masons working over a relatively short period of time. This assessment is supported by an analysis of stone supply that suggests that quarrying was organised in an ad hoc manner to supply local needs. These churches are normally placed within a broad timeframe spanning the tenth to early-twelfth centuries but a number of factors combine to suggest that the habitual styles are a relatively late development, perhaps mainly from the mid-eleventh century onwards. Some of the implications of this proposed refinement of the existing chronology are briefly discussed.