Guillaume de Baillou

Guillaume de Baillou (1538 to 1616), known in Latin as Ballonius, was a French physician born in Paris into the Baillou family, one of the oldest aristocratic families in Europe. He studied at the University of Paris as a pupil of Jean Fernel, took his Bachelor of Arts in 1568 and his medical doctorate in 1570, was an instructor in Paris for 46 years and eventually became dean of the Faculty of Medicine. For a period he was personal physician to Henry IV. He is considered the first epidemiologist since Hippocrates and is credited as the founder of modern epidemiology, having made extensive studies of the epidemics that struck Paris. He gave the first clinical description of pertussis, or whooping cough, in 1578, and the first modern descriptions of rheumatism and arthritis, in his treatise Liber de Rheumatismo et Pleuritide dorsali.