======Wolfgang Koos====== Born on 14th February 1930, to parents who were both teachers in Vienna, but many of his other relatives came from the medical profession. He received an excellent classical education. It was, however, his grandfather, a passionate zoologist, who drew the boy's attention to life sciences by introducing him to many species of wild life such as crocodiles, snakes and lions. Albert Schweitzer was his idol during those early years. At the age of sixteen, there was a decisive turn of events when Koos came across a report about the removal of a brain tumour by Harvey Cushing. From this point onwards, he knew the direction he wanted his career to follow. As a matter of constancy ± a virtue he excelled in throughout his life ± the young man started reading medicine at the University of Vienna in 1948 and graduated in 1954. His main interest focused on the human nervous system. All the rest of medicine was considered to a certain extent a necessary appendix. Whilst preparing to participate in a congress of neurosurgery, Koos made the acquaintance of Hugo Krayenbuhl, who was to become his [[mentor]], who invited him to [[Zurich]], [[Switzerland]]. The next stop in his career was Basel (Switzerland), where he stayed with Rudolf Nissen from 1955 to 1957. Supported by Nissen, James Watts accepted Wolfgang Koos as resident at the Department of Neurosurgery at George Washington University, Washington DC. Unlike the situation in Europe at that time, neurosurgery in the United States of America was already an independent, functionally orientated discipline founded on a broad scientiÆc basis. During that time he got in touch with Colonel Kempe, a neurosurgeon at the Walter Reed US-Army Hospital and neuropathologist Stochdorf, later on Professor of Neuropathology in Munich. He then went to Boston to study paediatric neurosurgery (which was to become his speciality) under the tutelage of Frank Ingraham and Donald Matson. Still in Boston, he established close contact with William H. Sweet. After having completed his training program as chief resident, Koos returned to his home country in June, 1960. On returning to Austria, the young neurosurgeon began to establish paediatric neurosurgery at Bad Ischl, Upper Austria. Three years later, he was entrusted with the foundation of a neurosurgical department at the provincial capital of Carinthia, Klagenfurt and served as Head of the newly founded department until he joined Herbert Kraus, Chairman of the newly founded Department of Neurosurgery at the University of Vienna Medical Centre, in 1964. In the following years Koos was responsible for the expansion and development of the department specialising in paediatric neurosurgery. In collaboration with neurosurgeons, Gerlach and Jensen, he wrote two books on paediatric neurosurgery, thus laying the foundation for paediatric neurosurgery to become a speciality in German-speaking countries. The highlight of these early e®orts in paediatric neurosurgery was the founding of the European Society for Paediatric Neurosurgery, which held its inaugural meeting in Vienna in 1968. In 1969, Koos revisited his mentor Krayenbuhl in Zurich, and collaborated with Gazi Yasargil to become one of the Ærst teams of neurosurgeons committed to microsurgery. In Vienna, Koos introduced the operating microscope at a time when microsurgery was still treated with scepticism. Nevertheless, the new technique rapidly become routine and, in 1973, Koos was invited as Associate Professor to his former training centre, the George Washington University, Washington DC, where he stayed for a year, introducing new possibilities opened up by this development. In 1978, Wolfgang Koos was appointed full Professor of Neurosurgery and Chairman of the Department of Neurosurgery of the University Medical Centre as successor to Herbert Kraus making it an institution of great international repute. Meanwhile, in Vienna and throughout Austria, neurosurgery became a generally accepted speciality, thus allowing Wolfgang Koos to realise step by step his dream of an entirely new neu- rosurgical institution built as part of the new University Medical Centre. Overseeing meticulously all stages of design and construction, he opened his new facilities on December 14, 1984. In the years prior to his retirement, all subspecialties of neurosurgery ± micro- surgery of the brain, spinal cord and peripheral nerves, stereotactic and functional neurosurgery, paediatric neurosurgery as a special interest, neuro-oncology, neuro-orthopaedics, neuro endocrinology, neurotraumatology, interventional neuroradiology and, since 1993, radiosurgery (Gamma Knife) ± were gathered to form a unit that o®ers the full spectrum of neuro- surgical procedures to a referral base encompassing central and eastern Europe. Wolfgang Koos' scientiÆc work is set out in more than 200 publications, and his neurosurgical textbooks have become a part of standard neurosurgical literature. Wolfgang Koos was a member of numerous medical societies, the American Association of Neurological Surgeons, The Royal Society of Medicine, Societe de Neuro-Chirurgie de Langue Francaise, Deutsche Gesellschaft und Österreichische Gesell- schaft fu » r Neurochirurgie, European Society for Paediatric Neurosurgery, International Society for Paediatric Neurosurgery and The New York Academy of Sciences to name but a few. From 1985 to 1988 he served as President of the European Society for Paedi- atric Neurosurgery, in 1989 and 1990 he became Pres- ident of the Austrian Society for Neurosurgery. Apart from a life devoted to neurosurgery and neu- roscience, the dream of Koos' youth, Africa, had still survived. Koos travelled a lot to Kenya but, un- fortunately, he could not complete a book about Afri- ca's lions he was working on. Perhaps the lions were also the background of Koos' preference for Chow- Chows. Together with his charming wife Ingrid who has been for many years a companion sharing all pas- sions with her husband and helped him especially in his last weeks of illness, Wolfgang Koos kept a pack of 8 to 10 Chow-Chows for recreation and counterbalance in his scarce leisure time. We have lost a talented neurosurgeon and scientist but above all a man with whom one could enjoy a conversation in private over a good dinner and a glass of Æne wine. Moreover, he was still an enthusiastic bi- ologist in a wider sense documented by his friendship with the Nobel prize winner Konrad Lorenz. Many colleagues in Austria, Europe and the world ± partic- ularly in the US ± have lost a passionate neurosurgeon, a loyal friend and dreamer, who turned his vision into reality. Wolfgang Koos will be remembered as one of the leading European neurosurgical personalities of the twentieth century