Peter Mark Roget LRCP FRS FRCP FGS FRAS (UK: /ˈrɒʒeɪ/ US: /roʊˈʒeɪ/;[1][2] 18 January 1779 – 12 September 1869) was a British physician, natural theologian, lexicographer, and founding secretary of The Portico Library.

In 1824, he read a paper to the Royal Society about a peculiar optical illusion which is often (falsely) regarded as the origin of the ancient persistence of vision theory that was later commonly, yet incorrectly, used to explain apparent motion in film and animation.

[4] Peter Mark Roget was born in Broad Street, Soho, London, the son of Jean (John) Roget (1751–1783), a Genevan cleric born to French parents, and Catherine "Kitty" Romilly, the sister of British politician, abolitionist, and legal reformer Sir Samuel Romilly.

[5] Samuel Romilly, who took on the role of surrogate father to Roget and supported his nephew's education, also introduced him into Whig social circles.

[5] Living in Clifton, Bristol, from 1798 to 1799, he knew Thomas Beddoes and Humphry Davy and frequented the Pneumatic Institute.

[5] With the help of Samuel Romilly, Roget became a private physician to William Petty, 1st Marquess of Lansdowne, who died in 1805.

[14] Roget was elected a Fellow of the Royal Society in 1815, in recognition of a paper on a slide rule with a loglog scale.

[15][16] The paper was noted by Michael Faraday and by Joseph Plateau, who both mentioned it in their articles that presented new illusions with apparent motion.

[17][18] It has often been heralded as the basis for the persistence of vision theory, which has for a long time been falsely regarded as the principle causing the perception of motion in animation and film.

[19] In 1834, Roget claimed to have invented "the Phantasmascope or Phenakisticope" in the spring of 1831,[20] a few years before Plateau introduced that first stroboscopic animation device.

[21] A chess player, in an article in the London and Edinburgh Philosophical Magazine Roget solved the general open knight's tour problem.