[15] Having been thrown into the sea tied to a mill stone, he miraculously arrived on the shores of Cornwall where he built his tiny oratory and continued his work of evangelism, founding communities.

[17][18]Joseph Loth has argued, on detailed philological grounds, that the names Piran and Ciarán could not possibly refer to the same person.

[18] The fourteenth-century Life of Saint Piran, probably written at Exeter Cathedral, is a complete copy of an earlier Middle Irish life of Ciarán of Saighir, with different parentage and a different ending that takes into account Piran's works in Cornwall, and especially details of his death and the movements of his Cornish shrine; thus "excising the passages which speak of his burial at Saighir" (Doble).

"[19] Also, the saint of the church in Exeter was Keranus or Kyeranus [Queranus] in Latin documents, with Kerrian being the local vernacular pronunciation.

David Nash Ford accepts the Ciarán of Clonmacnoise identification, whilst further suggesting that Piran's father in the Exeter life, Domuel, be identified with Dywel fab Erbin, a fifth-century prince of Dumnonia (Devon and Cornwall).

Exeter Cathedral was reputed to be the possessor of one of his arms, while according to an inventory, St Piran's Old Church, Perranzabuloe, had a reliquary containing his head and also a hearse in which his body was placed for processionals.

In 1443, Cornish nobleman, Sir John Arundell bequeathed money in his will for the preservation of the head of St Piran in the chapel at Perranzabuloe.

[28][29] Mount St. Piran is a mountain in Banff National Park near Lake Louise, Alberta, Canada, named after the saint.

In 2006 Cornish MP Dan Rogerson asked the government to make 5 March a public holiday in Cornwall to recognise celebrations for St Piran's Day.