After a long illness, Professor Jan Fousek passed away on September 4 2016. He was one of the most prominent researchers in the field of ferroelectricity within the last 50 years and certainly the best-known Czech representative of this field. Born in Příbram, Czechoslovakia, he graduated from the Faculty of Mathematics and Physics of the Charles University, Prague, in 1953 and became a Ph.D student in the newly established Department of Ferroelectrics of the Institute of Physics, Czechoslovak Academy of Sciences (CAS), under the supervision of Prof. J. Beneš. In 1958 he defended his Ph.D thesis on microwave dielectric properties of barium titanate. Shortly after he became the head of the Department of Ferroelectrics at the same institution – a position he kept until 1990. During his early career he organized and chaired the 1st International Meeting on Ferroelectricity (IMF-1), which took place in Prague in 1966. At that time his principal research concerned domain walls in classical ferroelectrics. This work culminated in his most cited paper on permissible ferroelectric domain walls connecting two mechanically compatible domains. From 1967 to 1968, he and his wife Anna (also a physicist in ferroelectricity) visited Prof. L. Eric Cross at Penn State University. During that time, his research revealed dielectric behaviour of gadolinium molybdate which initiated intense research on improper ferroelectrics that held a predominant role within the Department during the seventies. Professor Fousek was also involved in optical and electro-optical studies of ferroelectrics, including improper and pseudo-proper ferroelectrics and the related phase transitions. By the beginning of eighties, the research was extended to consider incommensurate ferroelectrics and phase transitions of modulated phases. After the Soviet occupation in 1968, travelling abroad in Czechoslovakia became extremely difficult, but thanks to Professor Fousek’s established contacts he and other colleagues at the CAS were able to make some scientific visits abroad. One important visit during this time was Professor Fousek’s stay at the ETH Zurich (Swiss Federal Institute of Technology) in 1977. Peter Günter at the ETH Zurich later invited Professor Fousek to return for several additional scientific visits. A new series of meetings also emerged: “European Conference on Applications of Polar Dielectrics” (ECAPD). The first ECAPD was held together with the “International Symposium on Applications of Ferroelectrics” (ISAF) in Zurich in 1988, chaired by P. Günter. Because international contacts were difficult to maintain in the seventies, Professor Fousek established regular bi-lateral meetings with Polish scientists, represented by Professor Bozena Hilczer, Institute of Molecular Physics, Polish Academy of Sciences, Poznan. Meeting have been held alternately between the two countries since 1979. In the eighties, Professor Fousek continued research on optical and electro-optical properties of various incommensurate systems, low-temperature ferroelectrics and ferroelectric liquid crystals. In collaboration with P. Günter’s team he also studied the photo-induced and photo-refractive effects in ferroelectrics. In 1994 Jan Fousek was promoted to Professor in the Technical University of Liberec (TUL) and joined the Department of Physics at the Faculty of Education TUL. He supervised several Ph.D. students, revived and stimulated the research in the field of piezoelectricity and ferroelectricity and initiated several successful grant applications for establishing a modern experimental infrastructure at TUL. Younger colleagues benefited from his international contacts and were able to initiate research stays abroad. He continued regular visits to Penn State University, where he began writing a book on domains, together with A. Tagantsev from EPFL Lausanne and E. Cross. The book “Domains in Ferroic Crystals and Thin Films” provides an impressive monography of about 800 pages and was published in 2010. This volume was his last and most prominent scientific achievement. He continued his appointment with TUL until his retirement in 2005, helped with the organization of the 7-th European Conference on Applications of Ferroelectric (ECAPD-7) at TUL in 2004 and the Conference on Piezoelectricity for End Users III (PIEZO2007), Liberec 2007. Professor Fousek’s death was felt world-wide throughout the scientific community even after his six-year, illness-imposed absence from research. Several international conferences will honour his memory with special sessions. He will be remembered as a founder of the Czech research on ferroelectrics and as the best-known Czech representative in this field. Jan Petzelt Institute of Physics CAS, Prague, Czech Republic