Church and chapel data from The Religious census of 1851 : A Calendar of the returns relating to Wales, Vol 11, North Wales. Ed. by Ieuan Gwynedd Jones, UWP, 1981. The names given towards the end of each entry are those of the informants.
Llangwyllog Parish; Statistics; Area 2301 acres; Population 108 males, 97 females, total 205
Llangwyllog Parish Church (Diocese of Bangor) Attendance - usual number 15/30 Service in Welsh Informant; A Ellis
LLANGWILLOG (LLAN-GWYLLOG), a parish partly in the hundred of LLYVON, partly in that of MENAI, and partly in that of MALLTRAETH, county of ANGLESEY, NORTH WALES, 3 miles (N. W.) from Llangevni, containing 267 inhabitants. This parish, which derives its name from the dedication of its church to St. Cwyllog, a female saint, who flourished in the middle of the sixth century, is pleasantly situated nearly in the centre of the island, and on the turnpike road leading from Llangevni to Llanerchymedd, from which places it is equidistant. A sanguinary battle is said to have taken place on Maes Rhos Rhyvel, in 1143, between the forces of Owain Gwynedd, Prince of North Wales, and the united armies of the Erse, Manks, and Norwegians, who had invaded the island, in which the Welsh prince was triumphantly victorious. Upon that occasion the whole naval force of Wales is said to have been brought into action, and to have succeeded in capturing all the ships of the enemy off Dulas bay. This victory is celebrated in Gray's ode to the memory of Owain Gwynedd, in which he eulogizes the exploits of that chieftain; but it is not noticed by any of the principal Welsh historians. This parish, which is of comparatively small extent, is enclosed, and the land is in a good state of cultivation. The living is a perpetual curacy, in the archdeaconry of Anglesey, and diocese of Bangor, endowed with £400 private benefaction, £600 royal bounty, and £800 parliamentary grant, and in the patronage of Sir R. B. Williams Bulkeley, Bart. The church, situated in that part of the parish which is in the hundred of Malltraeth, was originally founded in the year 605: the present edifice is small, but remarkably well built, and has an ancient and curious chapel at the west end of the nave. There are places of worship for Calvinistic and Wesleyan Methodists. The interest arising from some small charitable bequests and donations is annually distributed among the poor of this parish, pursuant to the directions of the several benefactors. At a short distance from Maes Rhos Rhyvel is a place called " Castell," the origin and history of which are equally unknown. Coins of Nero, Vespasian, and Constantine, have been found here at various times, in a state of good preservation, and in 1829 a gold coin of Vespasian was dug up, the impression on which was quite perfect. The average annual expenditure for the support of the poor is £185.5. ( A Topographical Dictionary of Wales by Samuel Lewis, 1833)
Trescawen estate papers - details of extant records on Archives Network Wales
"William Pritchard of Trescawen and Llaneilian, Anglesey, the son of Richard Thomas (d. 1722) of Trevor, Llansadwrn, is the first to be described as of Trescawen, in the parish of Llangwyllog......."
Llangwyllog Railway Station records;- Log books (photocopies) of William Hughes and Hugh Roberts, gangers at Llangwyllog station, 1895-1914.
"The Anglesey Central Railway, from Gaerwen to Amlwch, was built in 1862 and opened in 1864; it became a branch line of the London and North Western Railway Company in 1863, and in 1923 became part of London Midland and Scottish Railways.................................."
Jesus College, Oxford, Estates in Anglesey, Records - details of extant records on Archives Network Wales
"Include; Deeds and other documents relating to Tyn-yr-Onnen farm, Llangwyllog, 1607-1922; correspondence between Jesus College and Anglesey County Council relating to Tyn-yr-Onnen, 1948-1955....."