In 1939 they were requisitioned for wartime use, adapting and repairing flying boats, by Saunders-Roe, who continued after the war with a wide variety of light engineering activities.

An archaeological dig on the site in 1991 identified substantial buried remains of the friary church and other monastic buildings.

By the 900s it was the main town (Maerdref) and Royal Court (Llys) of the commote of Dindaethwy which covered the southeast quarter of Anglesey.

Control of the ferry crossing gave Llanfaes its wealth and prestige, and by the early 13th century it was a busy commercial town, probably centred around the Church.

[4] The first Franciscans arrived in Britain in 1224 as part of a missionary expansion of this new order of friars living a life of poverty and preaching.

All the earliest British foundations were small, often redundant or decayed premises, and there was an active resistance to prestige or permanence in their buildings.

[6] The Friary at Llanfaes was founded about 1237 AD, just as this early stress on poverty was beginning to be replaced by an acceptance of larger, well-funded premises, from donors eager to be associated with this lively new expression of Christian faith.

[3] As a result of these events, the friary became associated with female members of the royal family of Gwynedd, and in 1282 it was the burial place of Eleanor de Montfort, Princess of Wales.

It was further embroiled in the 1401 rebellion of Owain Glyndŵr, causing sufficient damage that the occupants were forced to vacate it for several years.

[3] The friary was dissolved in 1538 by Henry VIII,[9] and an inventory at that time indicates that, as well as the church, vestry, accommodation and refectory buildings, a substantial agricultural holding was in place.

The precinct boundary wall was still visible to John Speed in 1610, and the Friary church remained until the mid-nineteenth century, in use as a barn.

The panel above the coffin is inscribed: "This plain sarcophagus, (once dignified as having contained the remains of Joan, daughter of King John, and consort of Llewelyn ap Iowerth, Prince of North Wales, who died in the year 1237), having been conveyed from the Friary of Llanfaes, and alas, used for many years as a horsewatering trough, was rescued from such an indignity and placed here for preservation as well as to excite serious meditation on the transitory nature of all sublunary distinctions.

When Llanfaes was de-populated at the start of the 14th century, Henllys survived as a residence of note, and after 1460 it was granted to William Hampton, by then the Deputy Governor of Beaumaris Castle.

The combination of radar and the high powered searchlights enabled the planes to find and attack a U-boat before it could dive.

[22] One of the survivals from this time is a large concrete turning circle, just south of Fryars House, used when setting aircraft compasses.

By the 1990s this had become owned by Faun Group, who in 1997 opened a new works in Llangefni and the decaying wartime hangars and buildings finally fell into disuse.

Two trenches close to the circle proved particularly rich in finds relating to the friary graveyard and boundary wall.

The trenches south of the circle revealed nothing of interest apart from the trackway/road, and so that area was deemed permissible for the sewage treatment works to be built.