Gunnar Hjelholt described himself as an applied social psychologist and he was one of the pioneers in the development of European group dynamics. In Denmark he was both a mentor and a source of inspiration for a whole generation of organisational psychologists. He died in 2002 at the age of 82. The initiative to write this book was taken at a conference held in his memory, in which Gunnar Hjelholt's Danish and international collaboration partners participated. The book's first section presents an account of Gunnar Hjelholt based on a series of earlier interviews which the editors had with him. Two long articles draw a fascinating double portrait: partly of an enthusiastic and ardent professional, and partly of the group dynamics movement on which Hjelholt, with his untiring energy, honesty and uncompromising principles, set his definitive mark. In the book's second section, this double portrait is illustrated in seven contributions written by Hjelholt's collaboration partners and friends. The concluding third section presents a selection of Hjelholt's own articles written over a 35 year period.