Edward Lhuyd (pronounced ['d]; occasionally written as Llwyd in recent times, in accordance with Modern Welsh orthography) (1660 - 30 June 1709) was a Welsh naturalist, botanist, linguist, geographer and antiquary. He is also known by the Latinized form of his name, Eduardus Luidius.
Lhuyd was born in Loppington, Shropshire, the illegitimate son of Edward Lloyd of Llanforda, Oswestry and Bridget Pryse of Llansantffraid, near Talybont, Cardiganshire, and was a pupil and later a master at Oswestry Grammar School. His family belonged to the gentry of south-west Wales; though well-established, his family was not well-off, and his father experimented with agriculture and industry in a manner that brought him into contact with the new science of the day. Lhuyd attended grammar school in Oswestry and went up to Jesus College, Oxford in 1682, but dropped out before his graduation. In 1684, he was appointed assistant to Robert Plot, the Keeper of the Ashmolean Museum and replaced him as Keeper in 1690; he held this post until 1709.
Whilst employed by the Ashmolean he travelled extensively. A visit to Snowdonia in 1688 allowed him to construct for John Ray's Synopsis Methodica Stirpium Britannicorum a list of flora local to that region. After 1697, Lhuyd visited every county in Wales, and then travelled to Scotland, Ireland, Cornwall, and Brittany and the Isle of Man. In 1699, with financial aid from his friend Isaac Newton, he published Lithophylacii Britannici Ichnographia, a catalogue of fossils collected from places around England, mostly Oxford, and now held in the Ashmolean.
In the late 17th century, Lhuyd was contacted by a group of scholars, led by John Keigwin of Mousehole, who were trying to preserve and further the Cornish language and he accepted the invitation to travel to Cornwall to study the language. Early Modern Cornish was the subject of a study published by Lhuyd in 1702; it differs from the medieval language in having a considerably simpler structure and grammar.
In 1707, having been assisted in his research by fellow Welsh scholar Moses Williams, he published the first volume of Archaeologia Britannica: an Account of the Languages, Histories and Customs of Great Britain, from Travels through Wales, Cornwall, Bas-Bretagne, Ireland and Scotland. This book is an important source for its linguistic description of Cornish, but even more so for its understanding of historical linguistics. Some of the ideas commonly attributed to linguists of the nineteenth century have their roots in this work by Lhuyd, who was "considerably more sophisticated in his methods and perceptions than [Sir William] Jones''.
Lhuyd noted the similarity between the two Celtic language families: Brythonic or P-Celtic (Breton, Cornish and Welsh); and Goidelic or Q-Celtic (Irish, Manx and Scottish Gaelic). He argued that the Brythonic languages originated in Gaul (France), and that the Goidelic languages originated in the Iberian Peninsula. Lhuyd concluded that as the languages had been of Celtic origin, the people who spoke those languages were Celts. From the 18th century, the peoples of Brittany, Cornwall, Ireland, Isle of Man, Scotland and Wales were known increasingly as Celts, and are regarded as the modern Celtic nations today.
The Snowdon lily (now Gagea serotina) was at one time called Lloydia serotina after Lhuyd.
Cymdeithas Edward Llwyd, the National Naturalists' Society of Wales, is named after him.
On 9 June 2001 a bronze bust of Lhuyd was unveiled outside the University of Wales's Centre for Advanced Welsh and Celtic Studies in Aberystwyth, immediately adjacent to the National Library of Wales, by Dafydd Wigley, the former leader of Plaid Cymru. The sculptor was John Meirion Morris and the inscription on the plinth, carved by Ieuan Rees, reads EDWARD / LHUYD / 1660-1709 / IEITHYDD / HYNAFIAETHYDD / NATURIAETHWR ("linguist, antiquary, naturalist").