Donald Davies coined the term 'packet'. His choice of the word was most deliberate.

"I thought it was important to have a new word for one of the short peices of data which traveled seperately. This would make it easier to talk about them. I hit on the word packet in the sense of the small package."

June 7, 1924, Treorchy, Wales

May 28, 2000, Australia


His Character:

Donald Watts Davies was born in Treorchy in the Rhondda Valley, Wales. His father, a clerk at a coalmine, died a few months later, and his mother took Donald and his twin sister back to her home town of Portsmouth, where he went to school. Davies was a highly pragmatic scholar, one example of this was during his research years when deciding on the name 'packet', he actually asked two linguists in a research team in his lab to confirm that there were cognates in other languages.

Davies told Paul Baran several years after coining the phrase 'packet switching', that he had been thoroughly embarassed to hear of Baran's work after he had finished his own. He added, "Well, you may have got there first, but I got the name."

His Life:

Scientist who enabled computers to talk to each other, and so made the Internet possible.

After working with Alan Turing, the scientific genius who first conceptualised computer programming, Donald Davies went on to make one of the crucial breakthroughs that made possible modern computer communications. He pioneered packet-switching, which enables the exchange of information between computers, without which the Internet could not function.

When Davies was recommended for a Commonwealth Fund Fellowship in 1954, his senior officer described him as "outstanding not only in intellectual power but also in the range of his scientific, technical and general knowledge. He is equally unusual in his ability to apply this knowledge to mechanical and electrical design and even to the actual construction of complex equipment. He is, for example, one of the very small number of persons who could draw up a complete logical design of an electronic computer, realise this design in actual circuitry, assemble it himself (with a high probability that it would work as designed) and then program it and use it for the solution of computational problems." This breadth of interest and ability was a hallmark of his career.

Davies was author or joint author of four influential books in his areas of expertise, notably Computer Networks and their Protocols published in 1973. His contributions, in particular his work on packet-switching, were recognised by the British Computer Society, which conferred on him the John Player Award in 1974 and a Distinguished Fellowship in 1975; he became its technical vice-president in 1983. He was appointed CBE in 1983 and a Fellow of the Royal Society in 1987. He was a visiting professor at Royal Holloway and Bedford New College in 1987.

His versatility and his fascination with intellectual challenges and puzzles are evident in his private interests as well as in his formal computer work. Over the years these interests included the design and construction of noughts-and-crosses machines, which were considerable attractions at the annual NPL children's parties (the game was the subject of his first published paper, in 1950); historic cryptographic machines, particularly the German machines of the Second World War; and all puzzles and games capable of mathematical analysis.

His last project showed that his technical skills remained undiminished: he developed a simulator of the Pilot ACE for a modern personal computer, which was demonstrated earlier this month at a conference celebrating the machine's 50th anniversary, although sadly illness prevented Davies from attending.


1943 BS degree in Physics, with first class honours, from Imperial College, London.
1947 BS degree in mathematics, with first class honours, from Imperial College, London. Awarded the Lubbock Memorial Prize as the leading mathematician of his year at London University.
In between the two degrees he worked at Birmingham University on atomic research as an assistant to Klaus Fuchs, and at ICI Billingham. During his last year at university he attended a lecture by John Womersley, superintendent of the mathematics division of the National Physical Laboratory (NPL), about the ACE digital computer which was being developed there. Excited by the potential of the new technology, he immediately applied to join the group. In September, Davies joined the laboratory as a member of the small team, which was led by Alan Turing of Bletchley Park fame.
1950 Based on Turing's design, the gourps work eventually led to the Pilot ACE computer, which ran its first program on May 10, 1950; it was one of the first four or five electronic stored-program digital computers in the world, and certainly the first in London. Along with Ted Newman, Jim Wilkinson and others, Davies had played an important part in the detailed design and development of the machine, and its successor, the full-scale ACE. As computer development moved from the laboratory to industry, Davies's interests widened to include the purposes for which computers could be used. For example, he developed a road traffic simulator.
1954 Davies was recommended for a Commonwealth Fund Fellowship
1955 Married Diane Burton, the couple raised a daughter and two sons.
1958 Initiated a project to use a computer to translate technical Russian into English.
1963 Appointed technical manager of the advanced computer techniques project, responsible for government support for the British computer industry. His combination of managerial skills with technical ability led to rapid progress through the grades of the scientific Civil Service.
1966 Succeeded Albert Uttley as superintendent of NPL's autonomics division. He soon turned this into a division of computer science, giving it new and more practical objectives. The key new project was the development of an idea he had originated in 1965: that to achieve communication between computers a fast message-switching communication service was needed, in which long messages were split into chunks sent separately so as to minimise the risk of congestion. The chunks he called packets, and the technique became known as packet-switching. His network design was received enthusiastically by America's Advanced Research Project Agency (ARPA), and the Arpanet and the NPL local network became the first two computer networks in the world using the technique. Today's Internet can be traced back directly to this origin.

Davies was author or joint author of four influential books in his areas of expertise, notably Computer Networks and their Protocols published.


1974 His contributions, in particular his work on packet-switching, were recognised by the British Computer Society. which conferred on him the John Player Award
1975 British Computer Society confers on him a Distinguished Fellowship
1979 Davies was able to relinquish his managerial post at NPL to concentrate on technical work. Realising that computer networks would be used widely only if malicious interference could be prevented, he started a group to work on data security, concentrating on the new method of public key cryptosystems. The group built a strong consultancy role round his expertise; all the major British clearing banks, for instance, used its services.
1983 He became the British Computer Society's Technical VP in 1983, and was appointed CBE (Commander of the Order of the British Empire)
1984 Retired to continue his work as a data security consultant.
1987 Becomes a Fellow of the Royal Society. He was also a visiting professor at Royal Holloway and Bedford New College at this time.

Links: Interviews

Written by the THINK Protocols team, CS Dept, UT Austin
Please direct comments to Chris Edmondson-Yurkanan.