On this day: March 12

1820 village reports residents with blue skin linked to hereditary disorder

In March 1820, a rural village reported multiple residents with blue-tinged skin. Contemporary accounts and later medical study link the appearances to a hereditary methemoglobinemia variant rather than supernatural causes.

1894 Theater Incident Often Cited as First Documented Mass Hypnosis

On March 12, 1894, reports from a London music hall describe a sudden collective trance among audience members during a stage performance — an episode later cited in contemporary press and medical writings as an early documented case of mass hypnosis, though accounts and interpretations vary.

Panic at the Premiere: Early Horror Film Sparks Outcry

On March 12, 1931, the first public screening of a horror film reportedly provoked panic among some audience members—an event often cited in discussions of cinema’s early cultural impact and debates over film censorship.

1720: Marseille Records First Confirmed Return of Bubonic Plague in Europe

In March 1720, Marseille reported the first confirmed case of bubonic plague in Europe since earlier outbreaks, marking the start of a major epidemic that would devastate the city and influence public health measures across the continent.

Germany Annexes Austria in the 1938 Anschluss

On March 12, 1938, German troops entered Austria and the following day Austria was incorporated into Nazi Germany in an event known as the Anschluss, ending Austrian independence and marking a major step in Hitler’s expansionist policies.