John Kenneth Iliffe, Class of 1948

18 September 1931 – 16 February 2020

 John Iliffe was a notable early pioneer of computer science, a mathematician and a sportsman, who attended the City of London School between 1945 and 1948.

Born in Chingford in 1931, he gained a first class degree in the Mathematical Tripos at St John’s College, Cambridge in 1952 and served in the Royal Navy from 1953 to 1956. His first encounter with computers was with the University of Cambridge’s Electronic Delay Storage Automatic Calculator (EDSAC), and after his naval service he learnt more about the machines by running IBM’s service bureau in London. In 1958 he accepted an invitation to join the team building the R1 computer at Rice University in Houston, Texas, where he took responsibility for the operating system and language design and implementation. Among his innovations was the introduction of a data structure used to implement multi-dimensional arrays, now known as Iliffe Vectors and implemented in languages such as Java and Python.

Over the next 30 years he put into operation four computers demonstrating and evaluating new concepts in design, working mainly with Ferranti and ICL.  He held visiting academic appointments at Rice, Syracuse, Stanford, UC Davis and Imperial College, London. In 2000 he was awarded the Harry Goode Memorial medal by the IEEE Computer Society in recognition of his work.

John was a keen sportsman, notable at the school for his rugby (later having a few games for Saracens and playing for Combined Services Dartmouth) and swimming (later winning his half blue for swimming and water polo at Cambridge). Whilst still at the school he began training with Otter Swimming Club, and in later years played water polo with them, was a regular at their annual open water races, and served as club president from 1990 to 1996. At the age of 74 he completed the 11-mile swim of Windermere in the Lake District.

Having initially attended Chingford High, John came to CLS on winning a Carpenter scholarship. He was quite clear that his education at the school (far more than at Cambridge) was the significant event in determining the course of his career. In particular, he recalled C. G. Nobbs (Head of Maths and Second Master) and J. P. Stephenson (Head of Physics) as the two people who had had a more lasting influence upon his life than anyone before or since. Both assumed, without further discussion, that he would proceed to university: following Nobb’s example, he won a scholarship to St John’s.

John was happily married for over 60 years to Dorothy, with whom he had three children: Louise, Jonathan (CLS 1969-1976) and Kate. In the days when CLS masters routinely spanned two or more generations, he was still remembered and spoken of when his son started at the school some 20 years after he left. Being referred to as “Iliffe, son of the Iliffe” took a certain amount of getting used to.

He was a much loved man – quiet and thoughtful, but with a dry wit – and will be sadly missed by his children and grandchildren.