As of spring 2011, 150 years have passed since the death of one of the most famous neurological patients of the nineteenth century. A Frenchman, "Monsieur Leborgne" also known by the nickname "Tan," was hospitalized due to an almost complete loss of speech. His case was presented in 1861, during a seating of the Société d'Anthropologie de Paris by a physician, Pierre Paul Broca (1824-1880), who used this occasion to report that he had discovered, in the middle part of patient's left frontal lobe, the cortical speech center. This area was later named "Broca's area." Both the patient and his medical records were the subject of numerous descriptions and citations in the medical literature. The patient's full identity and social background has remained a mystery until now. This article presents biographical data concerning Leborgne and his family based on archive registers in France.