Richard Williams Morgan (bardic name "Mor Meirion", c.1815-c.1889) was a Welsh clergyman and author. He was born in Llangynfely, Cardiganshire and educated at Saint David's College in Lampeter. Morgan was a leading figure in the Celtic Revival "Gorsedd of Bards".
In 1874, Morgan was consecrated First Patriarch of a 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 prior to the Synod of Whitby while continuing his duties as an Anglican clergyman. In 1879 consecrated Charles Isaac Stevens (1835-1917), a former presbyter of the Reformed Episcopal Church as his successor as Patriarch of the Ancient British Church. The Ancient British Church in the UK persisted into the 1920s, with the Fifth Patriarch Herbert James Monzani Heard consecrated in 1922. A line of succession from Monzani survives in the small Ancient British Church in North America.
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, 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 the Rev. John Williams ('Ab lthel') as Hanes yr Hen Gymry, eu Defodau a’u Sefydliadau, 1858, and reprinted New York, 1860)
1858, Amddiffyniad yr iaith Gymraeg
1861, St. Paul in Britain or the Origin of the British as opposed to Papal Christianity (2nd ed. 1880)