After receiving his doctorate in medicine from the University of Padua, Harvey set up practice in London and later served as physician to James I and Charles I. In his De motu cordis (1628), considered one of the most significant scientific works ever published, Harvey demonstrated the circulation of blood by arguments based on observations of comparative anatomy and physiology, the use of tight ligatures for compression of arteries, and the first estimation of the volume of blood pumped by the heart. The epoch-making book undermined the Galenic system of medicine and set forth the founding principles of modern physiology.