Richard Williams Morgan
Morgan was ordained priest in October 1842, when he was appointed perpetual curate in Tregynon, Montgomeryshire (now Powys). An outspoken campaigner for the use of the Welsh language in schools and in churches, it was apparently his obduracy over this issue that in 1857 led to Morgan being refused communion in his own parish church in Tregynon. Although Morgan did not formally resign his curacy until 1862, he never again held an ecclesiastical post in Wales.
Like many Welsh Anglican clergy of his generation, Morgan was also active in the Celtic revival movement. As "Môr Meirion" he organised, along with his better-known cousin John Williams (Ab Ithel), an eisteddfod at Llangollen in 1858. But his presence among the organisers, at the height of the controversy over his attitude to the English bishops in Wales, had imperilled the plans.
In the late 1850s and the 1860s Morgan spent most of his time in London. In 1857 he published The British Kymry, or Britons of Cambria, a comprehensive but unorthodox history of the Welsh people from The Flood to the 19th century; and in 1861 St. Paul in Britain: or, the origin of British as opposed to papal Christianity. Morgan argued that St Paul himself had evangelised Britain and converted the British Druids; he claimed that therefore the ancient Church of Britain was coeval with that established by St Peter in Rome, and represented an apostolic succession independent of the Roman Church (the Catholic Church) that Augustine of Canterbury introduced to England in the sixth century.
In 1874, Morgan was consecrated First Patriarch of a reputed restored Ancient British Church by Jules Ferrette, the founder of the British Orthodox Church. Morgan took the religious name of "Mar Pelagius I" and undertook to revive the Celtic Christianity that existed prior to the Synod of Whitby while continuing his duties as an Anglican priest.
Also on 6 March 1879, Morgan consecrated Charles Isaac Stevens, a former Reformed Episcopal Church presbyter, as his successor as patriarch. Morgan was assisted in this consecration by Lee and Seccombe for the Order of Corporate Reunion.
The Ancient British Church in the UK persisted into the mid-twentieth century, with the Fifth Patriarch, Herbert James Monzani Heard (1866-1947), consecrated in 1922. Succession from Morgan's Ancient British Church is also found in the Free Protestant Episcopal Church (now the Anglican Free Communion).
- 1848, Maynooth and St. Asaph, or, the Religious Policy of the Conservative Cabinet Considered
- 1849, Notes on Various Distinctive Verities of the Church
- 1851, Ida de Galis: a Tragedy of Powys Castle
- 1851, Vindication of the Church of England: in Reply to Viscount Fielding
- 1853, Raymonde de Monthault, The Lord Marcher
- 1854, Christianity and Modern Infidelity (reprinted New York, 1859)
- 1855, The Church and its Episcopal Corruptions in Wales
- 1855, Correspondence and Statement of Facts Connected with the Case of the Rev. R. W. Morgan
- 1855, Scheme for the Reconstruction of the Church Episcopate and its Patronage to Wales
- 1856, North Wales or Venedotia
- 1857, The British Kymry or Britons of Cambria (translated into Welsh by Thomas Hughes and edited by the Revd John Williams (Ab Ithel) as Hanes yr Hen Gymry, eu Defodau a’u Sefydliadau, 1858, and reprinted New York, 1860)
- 1858, Amddiffyniad yr iaith Gymraeg (= A Defence of the Welsh Language)
- 1861, St. Paul in Britain or the Origin of the British as Opposed to Papal Christianity (2nd ed. 1880)
- 1867, The Duke's Daughter, a Classical Tragedy
Writing as H. H. Pelagius:
- 1869, The Church of England Communion Service: its Nullity and Profanity
- 1878, Altar Service of the British Church: Order of the Celebration of the Sacrifice of the Altar, or Holy Communion
- "Morgan, Richard Williams", The Dictionary of Welsh Biography to 1940 (1959), p. 393. 
- Peter Freeman, "The Revd Richard Williams Morgan of Tregynon and his Writings", Montgomeryshire Collections 88 (2000): pp. 87-93.
- G. H. Thomann, A Short Biography of the Reverend Richard Williams Morgan (c:1815–1889), the Welsh Poet and Re-founder of the Ancient British Church: An enquiry into the origins of neo-Celtic Christianity, together with a reprint of several works by Richard Williams Morgan and Jules Ferrette, etc., Solna, Sweden: St Ephrem's Institute (2001).
- Roger L. Brown, "Richard Williams Morgan: Patriarch, Priest and Romantic", in Parochial Lives: A Study in the 19th Century Welsh Church, Llanrwst: Gwasg Carreg Gwalch (2002), pp. 131-66.
- "The Anglican Free Communion: History". The Anglican Free Communion. Archived from the original on 24 September 2013. Retrieved 20 April 2013.
- "Welsh Biography Online: Morgan, Richard Williams". National Library of Wales. Retrieved 20 April 2013.