Christopher S. Strachey (; 16 November 1916 – 18 May 1975) was a British

computer scientist A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus ( ...

. He was one of the founders of denotational semantics, and a pioneer in

programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming l ...

design and computer

time-sharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.DEC Timesharing (1965), by Peter Clark, The DEC Professional, Volume 1, Number 1 Its emergence ...

.F. J. Corbató, et al.,
The Compatible Time-Sharing System A Programmer's Guide
' (MIT Press, 1963) . "the first paper on time-shared computers by C. Strachey at the June 1959 UNESCO Information Processing conference" He has also been credited as possibly being the first developer of a

video game Video games, also known as computer games, are electronic games that involves interaction with a user interface or input device such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device to gener ...

. He was a member of the

Strachey Strachey is a surname. Notable people with the surname include: Strachey family of Sutton Court, Somerset *John Strachey (d. 1674), friend of John Locke **John Strachey (geologist) (1671–1743), British geologist ***Henry Strachey of Sutton Cou ...

family, prominent in government, arts, administration, and academia.

Early life and education

Christopher Strachey was born on 16 November 1916 to

Oliver Strachey Oliver Strachey CBE (3 November 1874 – 14 May 1960), a British civil servant in the Foreign Office, was a cryptographer from World War I to World War II. Life and work Strachey was a son of Sir Richard Strachey, colonial administrator and ...

and Rachel (Ray) Costelloe in Hampstead, England. Oliver Strachey was the son of

Richard Strachey Sir Richard Strachey (24 July 1817 – 12 February 1908) was a British soldier and Indian administrator, the third son of Edward Strachey and grandson of Sir Henry Strachey, 1st Baronet. Early life He was born on 24 July 1817, at Sutton ...

and the great grandson of

Sir Henry Strachey, 1st Baronet Sir Henry Strachey, 1st Baronet (23 May 1736 – 3 January 1810) was a British civil servant and politician who sat in the House of Commons for 39 years from 1768 to 1807. Life Strachey was the eldest son of Henry Strachey, of Sutton Court, S ...

. His elder sister was the writer

Barbara Strachey Barbara Halpern Strachey (17 July 1912 – 15 October 1999 in Oxford, England) was a British author. Barbara Strachey was born to parents Oliver Strachey, a cryptographer in World War I and World War II, and the feminist politician, writer, and ...

. In 1919, the family moved to 51

Gordon Square Gordon Square is a public park square in Bloomsbury, London, England. It is part of the Bedford Estate and was designed as one of a pair with the nearby Tavistock Square. It is owned by the University of London. History and buildings The s ...

. The Stracheys belonged to the

Bloomsbury Group The Bloomsbury Group—or Bloomsbury Set—was a group of associated English writers, intellectuals, philosophers and artists in the first half of the 20th century, including Virginia Woolf, John Maynard Keynes, E. M. Forster and Lytton Strac ...

whose members included

Virginia Woolf Adeline Virginia Woolf (; ; 25 January 1882 28 March 1941) was an English writer, considered one of the most important modernist 20th-century authors and a pioneer in the use of stream of consciousness as a narrative device. Woolf was born ...

John Maynard Keynes John Maynard Keynes, 1st Baron Keynes, ( ; 5 June 1883 – 21 April 1946), was an English economist whose ideas fundamentally changed the theory and practice of macroeconomics and the economic policies of governments. Originally trained in ...

and Christopher's uncle

Lytton Strachey Giles Lytton Strachey (; 1 March 1880 – 21 January 1932) was an English writer and critic. A founding member of the Bloomsbury Group and author of '' Eminent Victorians'', he established a new form of biography in which psychological insight ...

. At 13, Christopher went to

Gresham's School Gresham's School is a public school (English independent day and boarding school) in Holt, Norfolk, England, one of the top thirty International Baccalaureate schools in England. The school was founded in 1555 by Sir John Gresham as a free ...

Holt Holt or holte may refer to: Natural world *Holt (den), an otter den * Holt, an area of woodland Places Australia * Holt, Australian Capital Territory * Division of Holt, an electoral district in the Australian House of Representatives in Vic ...

where he showed signs of brilliance but in general performed poorly. He was admitted to

King's College, Cambridge King's College is a constituent college of the University of Cambridge. Formally The King's College of Our Lady and Saint Nicholas in Cambridge, the college lies beside the River Cam and faces out onto King's Parade in the centre of the cit ...

(the same college as

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical c ...

) in 1935 where he continued to neglect his studies. Strachey studied mathematics and then transferred to

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...

. At the end of his third year at

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge beca ...

, Strachey suffered a nervous breakdown, possibly related to coming to terms with his homosexuality. He returned to Cambridge but managed only a "lower second" in the

Natural Sciences Tripos The Natural Sciences Tripos (NST) is the framework within which most of the science at the University of Cambridge is taught. The tripos includes a wide range of Natural Sciences from physics, astronomy, and geoscience, to chemistry and biology, w ...

Career

Unable to continue his education, Christopher joined

Standard Telephones and Cables Standard Telephones and Cables Ltd (later STC plc) was a British manufacturer of telephone, telegraph, radio, telecommunications, and related equipment. During its history, STC invented and developed several groundbreaking new technologies incl ...

(STC) as a research physicist. His first job was providing mathematical analysis for the design of electron tubes used in

radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...

. The complexity of the calculations required the use of a

differential analyser The differential analyser is a mechanical analogue computer designed to solve differential equations by integration, using wheel-and-disc mechanisms to perform the integration. It was one of the first advanced computing devices to be used operat ...

. This initial experience with a computing machine sparked Strachey's interest and he began to research the topic. An application for a research degree at the University of Cambridge was rejected and Strachey continued to work at STC throughout the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. After the war he fulfilled a long-standing ambition by becoming a schoolmaster at

St Edmund's School, Canterbury St Edmund's School Canterbury is an independent day and boarding school located in Canterbury, Kent, England and established in 1749. The extensive school grounds were acquired in 1855. The school currently caters for girls and boys aged 3–18, ...

, teaching mathematics and physics. Three years later he was able to move to the more prestigious

Harrow School Harrow School () is a Public school (United Kingdom), public school (English Independent school (United Kingdom), independent boarding school for boys) in Harrow on the Hill, Greater London, England. The school was founded in 1572 by John Lyon (sc ...

in 1949, where he stayed for three years. Christopher Strachey's Draughts Program

In January 1951, a friend introduced him to

Mike Woodger Michael Woodger (born 28 March 1923) is a pioneering English computer scientist. He was influential in the development of the early Pilot ACE computer, working with Alan Turing, and later the design and documentation of programming languages s ...

of the National Physical Laboratory (NPL). The lab had successfully built a reduced version of Alan Turing's

Automatic Computing Engine The Automatic Computing Engine (ACE) was a British early electronic serial stored-program computer designed by Alan Turing. It was based on the earlier Pilot ACE. It led to the MOSAIC computer, the Bendix G-15, and other computers. Ba ...

(ACE) the concept of which dated from 1945: the

Pilot ACE The Pilot ACE (Automatic Computing Engine) was one of the first computers built in the United Kingdom. Built at the National Physical Laboratory (NPL) in the early 1950s, it was also one of the earliest general-purpose, stored-program computer ...

. In his spare time Strachey developed a program for the game of

draughts Checkers (American English), also known as draughts (; British English), is a group of strategy board games for two players which involve diagonal moves of uniform game pieces and mandatory captures by jumping over opponent pieces. Checkers ...

(also known as "checkers"), which he finished a preliminary version in May 1951. The game completely exhausted the Pilot ACE's memory. The draughts program tried to run for the first time on 30 July 1951 at NPL, but was unsuccessful due to program errors. When Strachey heard about the

Manchester Mark 1 The Manchester Mark 1 was one of the earliest stored-program computers, developed at the Victoria University of Manchester, England from the Manchester Baby (operational in June 1948). Work began in August 1948, and the first version was operat ...

, which had a much bigger memory, he asked his former fellow-student Alan Turing for the manual and transcribed his program into the

operation code In computing, an opcode (abbreviated from operation code, also known as instruction machine code, instruction code, instruction syllable, instruction parcel or opstring) is the portion of a machine language instruction that specifies the operat ...

s of that machine by around October 1951. By the summer of 1952, the program could "play a complete game of Draughts at a reasonable speed". While he did not give this game – which may have been the first video game – a name,

Noah Wardrip-Fruin Noah Wardrip-Fruin is a professor in the Computational Media department of the University of California, Santa Cruz, and is an advisor for the Expressive Intelligence Studio. He is an alumnus of the Literary Arts MFA program and Special Graduate ...

named it "M. U. C. Draughts." Strachey programmed the first ever music performed by a computer; a rendition of the British National Anthem "

God Save the King "God Save the King" is the national and/or royal anthem of the United Kingdom, most of the Commonwealth realms, their territories, and the British Crown Dependencies. The author of the tune is unknown and it may originate in plainchant, ...

" on the Mark II

Manchester Electronic Computer The Manchester computers were an innovative series of stored-program electronic computers developed during the 30-year period between 1947 and 1977 by a small team at the University of Manchester, under the leadership of Tom Kilburn. They inclu ...

at Manchester, in 1951. Later that year, short extracts of three pieces were recorded there by a

BBC #REDIRECT BBC Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...

outside broadcasting unit: "God Save the King", "

Baa, Baa, Black Sheep "Baa, Baa, Black Sheep" is an English nursery rhyme, the earliest printed version of which dates from around 1744. The words have not changed very much in two and a half centuries. It is sung to a variant of the 1761 French melody '' Ah! vous dir ...

", and "

In the Mood "In the Mood" is a popular big band-era jazz standard recorded by American bandleader Glenn Miller. "In the Mood" is based on the composition " Tar Paper Stomp" by Wingy Manone. The first recording under the name "In the Mood" was released by ...

". Researchers at the

University of Canterbury The University of Canterbury ( mi, Te Whare Wānanga o Waitaha; postnominal abbreviation ''Cantuar.'' or ''Cant.'' for ''Cantuariensis'', the Latin name for Canterbury) is a public research university based in Christchurch, New Zealand. It was ...

, Christchurch restored the acetate master disc in 2016 and the results may be heard on

SoundCloud SoundCloud is an online audio distribution platform and music sharing website that enables its users to upload, promote, and share audio. Founded in 2007 by Alexander Ljung and Eric Wahlforss, SoundCloud is one of the largest music streaming s ...

. In May 1952, Strachey gave a two-part talk on "the study of control in animals and machines" (" cybernetics") for the

BBC Home Service The BBC Home Service was a national and regional radio station that broadcast from 1939 until 1967, when it was replaced by BBC Radio 4. History 1922–1939: Interwar period Between the early 1920s and the outbreak of World War II, the BBC ...

's ''Science Survey'' programme. Strachey worked for the

National Research Development Corporation The National Research Development Corporation (NRDC) was a non-departmental government body established by the British Government to transfer technology from the public sector to the private sector. History The NRDC was established by Attlee's Lab ...

(NRDC) from 1952 to 1959. While working on the St. Lawrence Seaway project, he was able to visit several computer centres in the United States and catalogue their

instruction set In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called a ...

s. Later, he worked on programming both the

Elliott 401 Elliott Brothers (London) Ltd was an early computer company of the 1950s–60s in the United Kingdom. It traced its descent from a firm of instrument makers founded by William Elliott (1780 or 1781-1853) in London around 1804. The research l ...

computer and the

Ferranti Pegasus Pegasus was an early British vacuum-tube (valve) computer built by Ferranti, Ltd that pioneered design features to make life easier for both engineers and programmers. Originally it was named the Ferranti Package Computer as its hardware design ...

computer. Together with

Donald B. Gillies Donald Bruce Gillies (October 15, 1928 – July 17, 1975) was a Canadian computer scientist and mathematician who worked in the fields of computer design, game theory, and minicomputer programming environments. Early life and education ...

, he filed three patents in computing design including the design of base registers for program relocation. He also worked on the analysis of vibration in aircraft, working briefly with

Roger Penrose Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus f ...

. In 1959, Strachey left NRDC to become a computer consultant working for NRDC,

EMI EMI Group Limited (originally an initialism for Electric and Musical Industries, also referred to as EMI Records Ltd. or simply EMI) was a British transnational conglomerate founded in March 1931 in London. At the time of its break-up in 2012, ...

Ferranti Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. The company was once a constituent of the FTSE 100 Index. The firm was known ...

and other organisations on a number of wide-ranging projects. This work included logical design for computers, providing

autocode Autocode is the name of a family of "simplified coding systems", later called programming languages, devised in the 1950s and 1960s for a series of digital computers at the Universities of Manchester, Cambridge and London. Autocode was a generic ...

and later the design of

high-level programming languages In computer science, a high-level programming language is a programming language with strong abstraction from the details of the computer. In contrast to low-level programming languages, it may use natural language ''elements'', be easier to use ...

. For a contract to produce the autocode for the

Ferranti Orion The Orion was a mid-range mainframe computer introduced by Ferranti in 1959 and installed for the first time in 1961. Ferranti positioned Orion to be their primary offering during the early 1960s, complementing their high-end Atlas and smaller syst ...

computer, Strachey hired

Peter Landin Peter John Landin (5 June 1930 – 3 June 2009) was a British computer scientist. He was one of the first to realise that the lambda calculus could be used to model a programming language, an insight that is essential to the development of both ...

who became his one assistant for the duration of Strachey's consulting period. In 1962, while remaining a consultant, he accepted a position at the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

. In 1965, Strachey accepted a position at the

University of Oxford The University of Oxford is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the world's second-oldest university in contin ...

as the first director of the

Programming Research Group The Programming Research Group (PRG) was part of the Oxford University Computing Laboratory (OUCL) in Oxford, England, along with the Numerical Analysis Group, until OUCL became the Department of Computer Science in 2011. The PRG was founded by ...

and later the university's first professor of computer science and fellow of

Wolfson College, Oxford Wolfson College () is a constituent college of the University of Oxford in England. Located in north Oxford along the River Cherwell, Wolfson is an all-graduate college with around sixty governing body fellows, in addition to both research an ...

. He collaborated with

Dana Scott Dana Stewart Scott (born October 11, 1932) is an American logician who is the emeritus Hillman University Professor of Computer Science, Philosophy, and Mathematical Logic at Carnegie Mellon University; he is now retired and lives in Berkeley, C ...

. Strachey was elected as a distinguished fellow of the

British Computer Society Sir Maurice Wilkes served as the first President of BCS in 1957 BCS, The Chartered Institute for IT, known as the British Computer Society until 2009, is a professional body and a learned society that represents those working in infor ...

in 1971 for his pioneering work in computer science. In 1973, Strachey (along with Robert Milne) began to write an essay submitted to the

Adams Prize The Adams Prize is one of the most prestigious prizes awarded by the University of Cambridge. It is awarded each year by the Faculty of Mathematics at the University of Cambridge and St John's College to a UK-based mathematician for distingu ...

competition, after which they continued work to revising it into book form. Strachey can be seen and heard in the recorded Lighthill debate on AI (see

Lighthill report __NOTOC__ ''Artificial Intelligence: A General Survey'', commonly known as the Lighthill report, is a scholarly article by James Lighthill, published in ''Artificial Intelligence: a paper symposium'' in 1973. Published in 1973, it was compiled b ...

). Strachey contracted an illness diagnosed as

jaundice Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme met ...

which, after a period of seeming recovery, returned and he died of infectious hepatitis on 18 May 1975. Strachey developed the concept of

in 1959. He filed a patent application in February that year and gave a paper "Time Sharing in Large Fast Computers" at the inaugural UNESCO Information Processing Conference in Paris where he passed the concept on to

J. C. R. Licklider Joseph Carl Robnett Licklider (; March 11, 1915 – June 26, 1990), known simply as J. C. R. or "Lick", was an American psychologistMiller, G. A. (1991), "J. C. R. Licklider, psychologist", ''Journal of the Acoustical Society of Am ...

. This paper is credited by the

MIT Computation Center The MIT Computation Center was organized in 1956 as a 10-year joint venture between the Massachusetts Institute of Technology and IBM to provide computing resources for New England universities. As part of the venture, IBM installed an IBM 704, whi ...

in 1963 as "the first paper on time-shared computers". He developed the

Combined Programming Language Combined may refer to: * Alpine combined (skiing), the combination of slalom and downhill skiing as a single event ** Super combined (skiing) * Nordic combined (skiing), the combination of cross country skiing and ski jumping as a single event * T ...

(CPL). His influential set of lecture notes ''

Fundamental Concepts in Programming Languages ''Fundamental Concepts in Programming Languages'' were an influential set of lecture notes written by Christopher Strachey for the International Summer School in Computer Programming at Copenhagen in August, 1967. It introduced much programming l ...

'' formalised the distinction between L- and R- values (as seen in the

C programming language ''The C Programming Language'' (sometimes termed ''K&R'', after its authors' initials) is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the language, as well as ...

). Strachey also coined the term ''

currying In mathematics and computer science, currying is the technique of translating the evaluation of a function that takes multiple arguments into evaluating a sequence of functions, each with a single argument. For example, currying a function f tha ...

'', although he did not invent the underlying concept. He was instrumental in the design of the

computer. He was a pioneer of early video games creating a version of

for the

Ferranti Mark 1 The Ferranti Mark 1, also known as the Manchester Electronic Computer in its sales literature, and thus sometimes called the Manchester Ferranti, was produced by British electrical engineering firm Ferranti Ltd. It was the world's first commer ...

. The macro language m4 derives much from Strachey's GPM (

General Purpose Macrogenerator A general-purpose macro processor or general purpose preprocessor is a macro processor that is not tied to or integrated with a particular language or piece of software. A macro processor is a program that copies a stream of text from one place ...

), one of the earliest macro expansion languages.

Legacy

The Department of Computer Science at the

has a Christopher Strachey Professorship of Computing, currently held by

Samson Abramsky Samson Abramsky (born 12 March 1953) is Professor of Computer Science at University College London. He was previously the Christopher Strachey Professor of Computing at the University of Oxford, from 2000 to 2021. He has made contributions to t ...

FRS. In November 2016, a ''Strachey 100'' event was held at Oxford University to celebrate the centenary of Strachey's birth, including a viewing at the

Weston Library The Weston Library is part of the Bodleian Library, the main research library of the University of Oxford, reopened within the former New Bodleian Library building on the corner of Broad Street and Parks Road in central Oxford, England. Histo ...

in Oxford of the Christopher Strachey archive held in the

Bodleian Library The Bodleian Library () is the main research library of the University of Oxford, and is one of the oldest libraries in Europe. It derives its name from its founder, Sir Thomas Bodley. With over 13 million printed items, it is the sec ...

collection.

Publications

* * * * * * * * * * * * * * * * Also: * Also: * Also: * * * * Also: *

References

External links

* * at the Virtual Museum of Computing
A simulator of the Manchester Mark 1, executing Christopher Strachey's Love letter algorithm from 1952

A web based version of Christopher Strachey's Love letter algorithm showing word lists

Higher-Order and Symbolic Computation
Volume 13, Issue 1/2 (April 2000) ''Special Issue in memory of Christopher Strachey''

in ''Resurrection''.

The Bulletin of the Computer Conservation Society The Computer Conservation Society (CCS) is a British organisation, founded in 1989. It is under the joint umbrella of the British Computer Society (BCS), the London Science Museum and the Manchester Museum of Science and Industry. Overview T ...

. Number 43. Summer 2008. ISSN 0958-7403.
Supplementary Strachey Papers
held at the British Library {{DEFAULTSORT:Strachey, Christopher 1916 births 1975 deaths People from Hampstead People educated at Gresham's School Alumni of King's College, Cambridge English computer scientists History of computing in the United Kingdom Members of the Department of Computer Science, University of Oxford Fellows of Wolfson College, Oxford Programming language researchers Programming language designers British computer programmers Schoolteachers from London Formal methods people Fellows of the British Computer Society

Christopher Christopher is the English language, English version of a Europe-wide name derived from the Greek language, Greek name Χριστόφορος (''Christophoros'' or ''Christoforos''). The constituent parts are Χριστός (''Christós''), "Jesus ...

LGBT scientists from the United Kingdom LGBT academics Deaths from hepatitis LGBT mathematicians 20th-century LGBT people Schoolteachers from Kent