The UK’s first connection to the Arpanet, a precursor to the internet, was made on 25 July 1973, when a computer at University College London transmitted packets of data to the Information Sciences Institute at the University of Southern California.

The man behind this milestone was Peter Kirstein, who has died aged 86. Often regarded as “the European father of the internet”, Kirstein played a significant role in the technology’s early experimental period, helping establish and expand the internet in Europe and other parts of the world.

Crucial to this role were Kirstein’s early connections with American internet pioneers including Vint Cerf, Bob Kahn and the original Arpanet developer Larry Roberts. Having studied at Stanford University in the 1950s, Kirstein established these networks in the mid-1960s and 70s, travelling to the US extensively for his job at General Electric (GE) first, and later for his research in computer communications.

In 1975 Kirstein and his research group at UCL participated in the first international test of the Transmission Control Protocol (TCP) and Internet Protocol (IP) to communicate with Stanford University. In 1977 these tests included also Norway; and in 1982, a year ahead of his American colleagues at Arpanet, Kirstein adopted TCP/IP, the protocol for reliable data transfer still used in today’s internet.

Kirstein was also responsible for setting up the Queen’s first email account, in 1976, at the opening of the new Royal Signals and Radar Establishment building in Malvern. “I asked my colleagues [at the Information Sciences Unit] in Marina del Rey, would they please set up an account, HME2, Her Majesty Elizabeth II, because anything else would be lèse-majesté,” he said in a recent interview. “All she had to do was press a couple of buttons, and her message was sent.”

Born in Berlin, Peter was the second child of Eleanor (nee Jacobsohn) and Walter Kirschstein, who were both dentists. His father was awarded the Iron Cross after volunteering at the age of 17 in the first world war.

However, after Adolf Hitler came to power, Peter’s parents realised that they were not safe in Germany because of their Jewish heritage. As their life deteriorated, the family decided to emigrate. Peter’s mother had UK citizenship, having been born in London, where her parents lived for a few years around the turn of the century. She left Germany in 1936 and set up a dental practice in London; Walter and the rest of the family, including Peter’s elder sister, Ellen, followed her in 1937. Ten years later, Walter became a British citizen and changed the family surname to Kirstein.

Peter was educated at Highgate school in north London. In December 1950 he was awarded a scholarship to study mathematics and electrical engineering at Gonville & Caius College, Cambridge; while waiting for his place the following year, he moved to California, where he lived with his aunt and uncle and briefly attended the University of California Los Angeles. He also found a part-time position working on a research project for the US army.

He graduated from Cambridge in 1954, and in the same year was awarded a fellowship in the electrical engineering department at Stanford University. There, he got his master’s degree in 1955, and his PhD in 1957, with a thesis on electron beams.

In 1959 he began working as a physicist at Cern, the European Organisation for Nuclear Research, in Switzerland. In 1963 GE was looking for a liaison scientist for their European office in Zurich. Kirstein perfectly fitted their requirements: proficiency in European languages, a background in electrical engineering and a thorough awareness of the US.

Kirstein was fluent in German and French and became competent in Russian during a six-month exchange with the Joint Institute for Nuclear Research at Dubna, a city 110km north of Moscow.

During his years at GE, Kirstein was responsible for evaluating European scientific research; it was there that he realised the growing importance of computer communications and in 1967 decided to return to academia to pursue research in this area; he got a senior position at the University of London Institute of Computer Science while he continued as a GE consultant for a further 25 years.

When the institute closed in 1973, he transferred his research group to UCL, where he became professor of statistics and computer science, moving physically with all the equipment in 1975. He founded the university’s computer science department in 1980 and served as its head until 1994.

Throughout his career Kirstein was involved in several international projects such as the Silk Project (2001), which provided dedicated internet infrastructure for research and educational communities in Caucasus and central Asia.

He was also responsible for the registration of the .uk domain in 1985 and he ran the domain affiliated with international users (.int) for several years.

Kirstein was appointed CBE in 2003 and was named an Internet Hall of Fame Pioneer in 2012.

He met Gwen Oldham, a dental hygienist, on a voyage from New York to London; they married in Los Angeles in 1958.

Gwen survives him, as do their daughters, Sara and Claire, six grandchildren, and Ellen.

• Peter Thomas Kirstein, computer scientist, born 20 June 1933; died 8 January 2020

• This article was amended on 25 March 2020 to give the full name of the University of Southern California.