Enn Tõugu was one of the young Estonian guys who were sent to Moscow and Leningrad to study computer science in the late 1950s, and who became pioneers in the field in the following decade. In his early years after returning from Leningrad, Enn Tõugu participated in the design and construction of the original STEM mini computer at the Institute on Pirita Road (Tallinn Institute of Electrical Engineering).

Started as a programmer, Enn Tõugu soon became a researcher whose research topics in the 1970s and 1980s focused on system programming, declarative languages, and artificial intelligence in the sense of that times. His research focused on describing knowledge as computational models and automatically composing algorithms based on them, using the technique known as structural synthesis of programs.

Although his important pioneering papers originally appeared in Russian, he is well known all over the world. His papers on computer software, artificial intelligence and cyber defense have been published in Estonian, Russian, English and Polish. He is the author of seven research monographs and over 200 research papers. He has also published dozens of essays and popular scientific writings. He and his students started software development and cyber defense that made Estonia famous.

Enn Tõugu lived a long and diverse life characterized by the title of his biography, published in 2017: Life as a Performance: Through Siberia and the Kremlin, to the Kingdom of Sweden.

Enn Tõugu was born in Tallinn on May 20, 1935. His father was a well-known lawyer. In 1941 the family was deported to Russia to the Kirov Oblast. While being deported he lost his parents, had to stay in an orphanage for some time, and started his schooling at a Russian-speaking village school. After returning to homeland, he grew up with his aunt's family near Tallinn in Haabersti. When choosing his specialty, he had to a certain extent take into account restrictions coming from being an exdeportee. A major in mechanics at the University of Technology was his opportunity. Thus Enn graduated as a mechanical engineer from TPI before committing himself to computer science.

He started his career at the Tallinn Excavator Factory, where he designed a mud pump and participated in the creation of a multi-bucket excavator, which made Estonia famous and is widely used in land improvement. This was followed by computer science studies in Leningrad followed in turn working at the Pirita Road Institute, the Institute of Cybernetics of Estonian Academy of Sciences and later alternately, Tallinn University of Technology, Royal University of Technology in Stockholm, Estonian Business School and NATO Collective Cyber ​​Defense Center of Excellence. Enn's research career was fast: he received a PhD in engineering in 1965 and a doctorate in engineering in 1973. He was awarded the professorship in 1978 by the USSR Higher Attestation Committee. He was elected a member of the Estonian Academy of Sciences in 1981 and a member of Ac Academia Europeae in 2010.

In parallel to his research at the Institute of Cybernetics, he began his teaching career at the University of Technology and continued as a professor in Sweden from 1992 to 2000 and then again in Estonia. Enn Tõugu's main contribution to educating scientists and engineers has been 21 candidate and doctoral theses and dozens of master's theses defended under his supervision. Through this he helped to establish a strong computer science school in Estonia, which in turn became the basis for the emerging IT industry. The strong legacy of the School of Computer Science, already established in pre-independence Estonia, made it possible for Estonian researchers to quickly reorient themselves. The foundation Enn Tõugu helped to create stands also indirectly behind the success of Estonian IT start-ups. His activities have influenced all software engineers and computer scientists educated in Estonia a few decades ago. In addition to his dissertation supervision, his teaching included the component of bringing up a scholar and decent human being with ethical beliefs that do not always guarantee success in the modern academic culture following the elbow law, but gives priority to persistent values.

Enn Tõugu's activities were far from being limited to science. He was interested in developments in society and published articles on social issues along with popular science articles in the Estonian press. As a representative of scientific and technical societies, he became a deputy to the Congress of People's Deputies of the USSR from 1989 to 1991. In Moscow, he joined the Estonian fraction and contributed to the struggle for independence. In 1996 Enn Tõugu was a candidate in the Estonian presidential elections.

In 1965 Enn Tõugu was awarded the Estonian SSR State Prize. One of the few Estonian scientists, he was awarded the State Prize of the USSR (1987). In 1987 he was awarded the Order of Honor, in 1995 the Medal of the Estonian Academy of Sciences and in 2001 the 3rd Order of the White Star. In 2017, he was awarded the National Science Award for his long-term productive research and development, the so-called lifetime award.

Enn Tõugu was a passionate offshore sailor, captain of a sailing ship and was a member of, among other things, the Moscow Olympic Games Tallinn Sailing Regatta. He was always praising to colleagues at the University and Academy of Sciences the discussions from the Pirita Yacht Club, which he regularly visited during his retirement. His interest in developments in the world, and especially in information technology and the information society, was extremely strong and did not cease when his physical health worsened.

We commemorate our teacher, outstanding scientist and dear colleague, and extend our condolences to his loved ones.

Estonian Academy of Sciences
Tallinn University of Technology
Department of Software Science
Department of Cybernetics