Archives Biographies: Alan Turing

Early years

Conceived in India, Alan Mathison Turing was born in London on 23 June 1912, to parents Julius Mathison Turing, who was a member of the Indian Civil Service, and Ethel Sara Turing, daughter of Edward Waller Stoney, chief engineer of the Madras Railways. He had one elder brother, called John. 

Turing’s genius was apparent from an early age and when he was 14 he was enrolled at Sherborne School, a public boarding school in Dorset. Unfortunately, Turing's natural inclination toward mathematics and science did not earn him respect with some of the teachers at Sherborne, whose definition of education placed more emphasis on the classics. Teachers also constantly complained of his untidiness. 

However, Turing continued to show remarkable ability in the studies he enjoyed, solving advanced mathematical problems in 1927 at the age of 16, without even having studied elementary calculus. 

King’s College, Cambridge

Turing matriculated at King’s College Cambridge in 1931 and graduated in 1934 with a distinguished degree in mathematics. A year later he was elected a fellow of Kings on the strength of a dissertation on ‘The Gaussian Error Function’. It was while a fellow at Cambridge that Turing developed what are now known as ‘Turing machines’, basic abstract symbol-manipulating devices which, despite their simplicity, can be adapted to simulate the logic of any computer algorithm. They are the basis for all modern computing systems.

From 1936 to 1938 Turing had a brief hiatus from Cambridge by spending time obtaining a PhD from the Institute for Advanced Study, Princeton University, which continued his work on the Turing machine. His dissertation introduced the notion of relative computing, where Turing machines are augmented with so-called oracles, abstract machines used to study decision problems that cannot be solved by a Turing machine. 

In addition to writing his dissertation, Turing studied cryptology and worked on an electro-mechanical binary-multiplier. When he returned to Cambridge, Turing studied under Ludwig Wittgenstein and started to work part-time for the Government Code and Cypher School (GCCS), a British intelligence agency.

Second World War and Bletchley Park

On the outbreak of the Second World War, he became heavily involved with breaking German cyphers at Bletchley Park, the war-time centre of GCCS. He had a significant role in breaking down the Enigma Machine by designing the ‘bombe’, the principle aid in deciphering Enigma messages. 

In July 1939 he had been part of a team which went to Poland to examine the Polish ‘bomba’, which the English ‘bombe’ was based on. The ‘bombe’ was an electromagnetic relay machine, being used to find the original settings of the encrypting Enigma, which were then tried on a British version of the Enigma. Turing’s bombe was installed in 1940, and by the end of the war, over 200 were in operation around the country. Turing was awarded an OBE in 1945 in recognition of his war-work.

Post Second World War

Immediately after the war, Turing worked on the development of the Automatic Computing Engine (ACE) at the National Physical Laboratory and in 1948 he was appointed to a Readership in the University of Manchester, to assist with the construction of a computing machine by leading the mathematical side of the work. A year later he was deputy director of the computing laboratory in Manchester and worked on the software for the Manchester Mark 1, one of the earliest computers. 

Also during this time, he continued to do more abstract work, investigating the concept of artificial intelligence. In 1950 he proposed an experiment, now referred to as the ‘Turing Test’, in an attempt to define a standard for machine intelligence. If a computer could fool a person into thinking they were conversing with another human rather than a machine, then that computer could be perceived as intelligent. 

In his seminal paper, ‘Computing Machinery and Intelligence’, Turing suggested that the best way to simulate an adult mind in a machine would be to build a program to simulate a child’s mind and then educate it.

Turing was elected a Fellow of the Royal Society in 1951. From 1952 he worked on mathematical biology and morphogenesis, the growth and form of living things, particularly Fibonacci phyllotaxis, the existence of Fibonacci numbers in plant structures.

Last days

Turing was homosexual, in an age when sexual relations between men were illegal. In 1952 he was convicted of gross indecency under Section 11 of the Criminal Law Amendment Act 1885. This led to him losing his job at Bletchley Park, and in 1954, he committed suicide by eating a cyanide-laced apple. 


The Turing Award, given by the Association for Computing Machinery every year since 1966, is considered to be the Nobel Prize of the computing world. Turing has also been honoured by a number of universities; several have buildings and laboratories named after him, including Oxford Brookes University and Los Andes University in Bogota, Columbia, and the University of Surrey, Guildford has a life-size statue of Turing on their campus.

After the refurbishment of IET London: Savoy Place, our new 175 seat lecture theatre was also named after Turing.

The IET and BCS Turing Lecture

Whilst Turing was not a member of the IEE in honour and recognition of his contribution in the field of computing, the IEE and the British Computer Society (BCS) established the Turing Lecture with the first lecture presented in 1999. It is a world leading event, now part of our EngTalks lecture series, presenting a topic from current research in computer science and given by an acknowledged expert in the field. It is usually toured around UK cities with some of the lectures in the past being held in Cardiff, Edinburgh, Glasgow and Manchester. 

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