To most physicians, Thomas Willis (1621–1675) is only known for the Circle of Willis, but he achievedmuch more: he was one of the three great clinicians of 17th-century England, and the founder of modernbrain anatomy and clinical neurology. He coined the word “neurology,” discovered reflex action, and wrotethe first textbook of clinical neurology. He made use of an imaginary neurophysiological framework whichenabled him to anticipate numerous discoveries of the 19th century.The first two chapters of the clinical part of his textbook deal with headache. Wolff's hypothesis,“complete migraine,rdquo; the slow spreading of focal symptoms, the cerebral origin of vomiting, and clusterperiodicity are found to be anticipated, at least in part. The combination of hypothetical pathophysiologyand arbitrary nosology is quite suggestive of the present situation, although the system is different.The review is based on the original Latin text of 1672.