Most medical doctors have heard of the Magnus and De Kleijn reflexes during their studies and may be aware of their relation to posture. But they tend to know little about their significance and nothing about the man who unravelled the complex physiology of these reflexes and his work. Rudolf Magnus lived from 1873 until 1927. His work on the physiology of posture was initiated during a short period with Sherrington in Liverpool in 1908. Though Magnus was also an authority in the field of pharmacology, it was particularly his neurophysical work on posture which made him known worldwide. It led to his nomination, together with De Kleijn, for the Nobel Prize in 1927. Unfortunately he died before the decision was made. In this illustrated biography Magnus’ family background and his student years are examined. Fragments of the diary of his journey to England in 1898 and the description of his scientific career in Heidelberg should enlighten those interested in how science was conducted during his lifetime. His lectures on Goethe as a scientist are also included. These are followed by a description of Magnus’ life as a professor of pharmacology in Utrecht, and his studies on animal postures and experimental pharmacology. The text concludes with an examination of Magnus’ legacy.