Sir John Williams, 1st Baronet (6 November 1840 – 24 May 1926), was a Welsh physician, who attended Queen Victoria of the United Kingdom and was raised to the baronetcy by her in 1894. He is remembered chiefly for his contribution to the collection of the National Library of Wales. He resided for part of his life at Plas Llanstephan, Carmarthenshire, a house he acquired by lease. Education and medical career John Williams was born in Gwynfe hamlet, Carmarthenshire, the son of David Williams (1802–1842), a Welsh Congregational minister, and his wife, Eleanor. He had four siblings. His father's elder brother, Morgan Williams (1800–1892) had 11 children, John's first cousins. Williams went to school in Swansea, then to the University of Glasgow, and finally to University College Hospital, London, to complete his medical studies: among other disbursements on his death he bequeathed £2,000 to the University College Hospital, London. In 1886 he became a private doctor to the royal family. As well as his career as an obstetric surgeon in London, he helped set up a Welsh hospital in South Africa during the Boer War, and was involved in the campaign against tuberculosis in his native country. Williams was invested as a Knight Commander of the Royal Victorian Order (KCVO) during a visit to King Edward VII at Sandringham House on 29 December 1902, and was later promoted to a Knight Grand Cross (GCVO) of the order. Bibliographical interests Sir John's leisure hours were largely spent in the acquisition of a large private library, and in 1898, influenced by the palaeographer John Gwenogvryn Evans, he acquired the Hengwrt–Peniarth collection of manuscripts. These were donated to the new National Library of Wales when it was built at Aberystwyth. In 1907 he was appointed the first President of the National Library, and two years later moved to Aberystwyth to live. In 1913 he became President of the University College of Wales, Aberystwyth (now Aberystwyth University). On his death, he bequeathed the remainder of his books, plus a large sum of money, in trust to the National Library, and the other moiety of the residuary estate in trust to the University College of Wales. Sir John presented a collection of some 1,200 manuscripts in total to the National Library, which divide into three groups: the 500 manuscripts from the Hengwrt–Peniarth collection; the Llanstephan collection of 200 manuscripts, including 154 from the Shirburn Castle