Both Geraint and Gerennius must be distinguished from Gerontius, prince of Dumnonia, to whom St. Aldhelm wrote at the request of an English synod in 705 urging him to abandon the Celtic method of determining Easter and the Celtic tonsure which the saint described as the tonsure of Simon Magus. All three (who are here distinguished as Geraint, Gerennius and Gerontius, though the names are identical) were historical personages and worthy of the veneration of after ages. For our present purpose it is not material to determine the identity of St. Gerrans: it is sufficient for us to know that Dingerein may be derived from any one of them. In the ninth century Dingerein or Dinurrin was the seat of the Abbot-bishop Kenstec. In the absence of evidence to the contrary we may suppose that his episcopate was concentrated at Gerrans and embraced the lands or parishes bordering the estuary of the Fal—those parishes in fact which subsequently became for ecclesiastical purposes the deanery of Penryn, and for civil purposes formed a large portion of the hundred of Trocayr or Tregeare. There is nothing to show that, either for ecclesiastical or for civil purposes, there were close relations, much less that there was a bond of union, between the Gerrans territory and that of Pawton, Pydar, St. German or Lawhitton. Gerrans was self-contained and independent. It may have retained, and probably did retain, traces of its episcopal character until Edward the Confessor, by charter, transferred the Cornish diocese with its lands and parishes to the see of Exeter. Some justification was doubtless required for the annexation of so much land in and around Gerrans to the bishop’s demesne, and the only justification which is apparent is that it was already regarded as such.[73]
In the case of St. Gerrans hardly any trace was left of its monastic and episcopal associations. In the _Taxatio_ of 1291 the benefice of St. Gerrans consisted of two portions, the rector’s and the prior of St. Anthony’s, which may point to a corporate life at an earlier date.
A glance at the map of Cornwall, in the light of what has been said, reveals, at the time of the Domesday Survey, present or past activities, on a considerable scale and monastic in character in every part of the county except in the north-east, and in the promontories of the Lizard and of the Land’s End.