Guillaume de Baillou

Guillaume de Baillou, known in Latin as Ballonius (1538 to 1616), was a French physician born in Paris into 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, taught in Paris for forty six years and 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 a founder of modern epidemiology for his 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, which he set out in his treatise Liber de Rheumatismo et Pleuritide dorsali.