In 1986, Oliver Padel coined the phrase ‘recurrent adjacency’ to describe

This ‘geographical dimension to the dedications of Brittonic saints’ was of particular interest to Gilbert Hunter Doble (1880–1945) and Emrys George Bowen (1900–1983), as well as, earlier on, to a range of Breton and Welsh scholars. The greatest nexus of clusters of ‘adjacent’ dedications is between Cornwall and Brittany (with some found also in Wales as well as in Devon). These two regions in particular are replete with notably obscure ‘saints’, often known only as church dedications or from place-names. Cults found across both regions are therefore all the more striking. Some of these shared cults may arise from early medieval emigration from Britain to Brittany. This is difficult to prove in specific cases while being a broadly reasonable assumption. Close contact between Cornwall and Brittany persisted, of course, through the medieval into the modern periods and may be responsible for later installations and conflations of saints’ cults.

The investigation of the geographical patterns of dedications to saints has changed considerably since the inspiring but perhaps somewhat naive work of Doble and Bowen. Their approach to patterns of dedications to saints as showing for the most part the movements of the saint himself or herself has been abandoned for more critical approaches. First, the dedications themselves are now somewhat more critically established according to linguistic and historical criteria. Second, they are viewed as a geographically and chronologically sensitive map of a cult over time. Only within this critical context are dedications related, if possible, to the actions of the saint in question, or to those of his immediate followers.

Place-names are a valuable category of evidence – and for Cornwall and Brittany invaluable, given the relative paucity of other types of evidence – especially for the cults of saints; but their primary, early character can be overstated.