Although his contributions to movement disorders were limited, Sydenham's name is historically linked to the field because of the well-known eponym, Sydenham's chorea. Born in 1624, Sydenham was a strong advocate of observation and empiricism who shunned contemporary, often elaborate, theories on medical illness. He was practical and relied on bedside experience more than book learning. Particularly interested in epidemic illnesses, he documented the rhythmic periodicity of malaria, scarlatina, and measles, and, as such, he can be viewed as a very early medical epidemiologist. Sydenham's last publication (1686) Schedula Monitoria included his now famous description of chorea minor, an entity that later was linked to his name largely due to the use of this designation by Charcot. An advocate of the healing properties of fresh air, Sydenham also was an active adherent to blood-letting therapy, prompting Char-cot to exclaim in 1888: "Let us throw a veil over Sydenham's therapeutic discussions on bleeding, bleeding and more bleeding. It makes your hair stand on end. How did those little English children survive all that?" As part of the International Congress of the Movement Disorder Society in Barcelona, June 2000, the society sponsored an exhibit devoted to History of Movement Disorders. With the help of numerous members of the MDS and loans from libraries, private collections, and laboratories, the authors developed a series of explanatory panels, accompanied by photographs, diagrams, and original artifacts that traced the early history of movement disorders from several perspectives. These materials have been adapted for publication in Movement Disorders and are presented in an ongoing series.