The settlement is traditionally credited to its
patron saint, a disciple of
Saint Beuno, who was supposed to have been
resurrected nearby. Both Aelhaiarn and Beuno were noble monks from
Powys who came north under the patronage of
King Cadfan of
Gwynedd. They settled in the area of
Clynnog and Llanaelhaearn after Cadfan's son
Cadwallon reneged on a promised grant elsewhere; his cousin, shamed by his behaviour, made good on his promises by donating his own land for their
monastery. The nearby
Afon Erch includes a stone whose
petrosomatoglyph is traditionally taken to represent the marks of the kneeling
Saint Beuno, worn through during his nightly visits to pray in the middle of the stream. It is listed as
Grade II*. During expansion of the churchyard in 1865, workers discovered the Latin-inscribed gravestone of an Aliortus of
Elmet, possibly indicating the existence of a religious settlement at the site before the arrival of Beuno's followers. St Aelhaiarn's
Well ('''') was a major station on the northern
pilgrimage route to
Bardsey Island and much frequented for the miraculous cures associated with the "laughing" or "troubling of the water", an irregular appearance of upwelling bubbles throughout its basin. By the 19th century, the Llanaelhaearn well was surrounded with an oblong basin and stone benches; devotees would rest on them while waiting for the water to "laugh". A
diphtheria outbreak in 1900, however, caused the local council to, first, enclose and roof the well and, then, to lock it away from the public. the present enclosure dates from 1975. ==Governance==