Born in Hanau, Germany, in 1614, Franciscus (Dele Boë) Sylvius received his medical doctor diploma from Basel University in 1637 and became Professor of Practical Medicine at Leiden University in 1658. One of the founders of medical biochemistry, Sylvius was also an outstanding anatomopathologist, with contributions ranging from the first description of the pulmonary tubercles to that of the lateral fissure of the brain. Thanks to Sylvius, a gifted teacher and one of the greatest physicians of his time, Leiden became a major European medical training center. He died in 1772 after having served as Rector Magnificus at Leiden University.