Donald Davies

Donald Watts Davies CBE FRS
Born	(1924-06-07)7 June 1924 Treorchy, Glamorgan, Wales
Died	28 May 2000(2000-05-28) (aged 75) Esher, Surrey, England
Alma mater	Imperial College
Known for	Packet switching
Awards	CBE FRS Distinguished Fellow, BCS
Scientific career
Fields	Computer science
Institutions	National Physical Laboratory

Donald Watts Davies, CBE FRS (7 June 1924 – 28 May 2000) was a Welsh computer scientist and Internet pioneer who was employed at the UK National Physical Laboratory (NPL).

During 1965-67 he invented modern data communications, including packet switching, high-speed routers, communication protocols, hierarchical computer networks and the essence of the end-to-end principle, concepts that are used today in computer networks worldwide. He envisioned, in 1966, that there would be a "single network" for data and telephone communications. Davies proposed and studied a commercial national data network in the United Kingdom and designed and built the local-area NPL network in 1968-69 to demonstrate the technology. Many of the wide-area packet-switched networks built in the 1970s were similar "in nearly all respects" to his original 1965 design. Davies' work influenced the ARPANET in the United States and the CYCLADES project in France, and was key to the development of the data communications technology used in Internet, which is a network of networks.

Davies' work was independent of the work of Paul Baran in the United States who had some similar ideas in the early 1960s, and who also provided input to the ARPANET project, after his work was highlighted by Davies' team.