Things that happened for which scenario planning was or might have been useful on this date in history.
537: Ostrogoths begin a siege of Rome. Belisarius almost gets caught outside the walls, but makes it inside in time to lead a successful long-term resistance to the siege (probably thanks to a primitive form of scenario planning).
1484: The College of Arms or Herald's College is established in England by Richard III just in time to get him a family crest before he is killed (due undoubtedly to a dire lack of scenario planning) at Bosworth Field and buried, again due to a tragic lack of scenario planning, under what would become a parking lot in Leicester.
1791: A semaphore machine is unveiled in Paris that will allow the revolutionary government to communicate with record speed across Europe. The first message is "Si vous reussissez, vous serez bientot couverts de gloire," which very roughly translates as, "The scenario planning workshop will cover you in glory." In 1794 the system will carry news of a French victory from the Belgian border to Paris in less than an hour.
1855: Alexander II is coronated as Tsar of Russia. He is assassinated 26 years later...due to a dire lack of scenario planning no doubt.
1882: Queen Victoria narrowly escapes an assassination attempt, thanks to outstanding scenario planning.