When at night I go to sleep / Fourteen angels watch do keep1

E very year, on Whit Tuesday, pilgrims crowd the small town of Echternach, Luxembourg, to join a Dancing Procession, a tradition, legend has it, rooted in miraculous healings as far back as the 8th century at the site of Saint Willibrord's sarcophagus. The procession, first mentioned in the city archives in 1497, moves rhythmically, three steps forward, two steps back, and slowly–five steps needed to advance one–the folk dancers, four or five abreast, holding on to each other. Willibrord, known as Saint Witt (Vitus) in Germany and as Saint Guy in France, was an English missionary to Den-mark and the Netherlands and the first Bishop of Utrecht, who founded the Benedictine Abbey of Echternach. Word of healings at his graveside spread far and wide: a woman brought there unable to walk left " using her own legs. " A man with fainting spells and tremor in the limbs was cured. Willibrord became the patron saint of patients with neurologic diseases: paresis, epilepsy, and what was then known as choreomania or the " dancing disease, " an epidemic of strange behavior of crowds. They would suddenly form circles and dance to exhaustion, " their limbs jerked and they collapsed snorting, unconscious and frothing. " This epidemic of uncontrolled dancing spread throughout Germany and the Netherlands. Outbreaks also occurred in France and Britain. " Peasants left their ploughs, merchants their workshops, and housewives their domestic duties to join the wild revels. " Paracelsus (1493–1541) described the dancing mania as chorea (Gr. χορεíα = dance) Sancti Viti and raised it from superstition to a disorder manifested in three types, one of them, chorea naturalis (arising from physical causes). The dancers were not uniformly hysterical. Some, who exhibited neurologic symptoms of unknown origin, were removed from the procession by the authorities. Others were the relatives and friends of the sick, who danced for the healing of their beloved. Felix Platter, in his Praxeos Medicae (1602), referred to Saint Vitus' dance as " that frightening and remarkable though rare disease, " an epidemic in which not just women but men too were afflicted with dancing that went on for weeks. He noted a possible parallel with a peculiar " jumping condition of the limbs, " known to the Arabs and concluded that if this disease is not from the devil, it must come from God himself as punishment. The term Saint Vitus' dance became popular …