The world will end in 1186

The so-called Toledo Letter supposedly written by the astrologers of Toledo and addressed to Pope Clement III began circulating throughout Europe in 1184. It predicted the end of the world would occur in September 1186. It said there would be wind and storms, drought and famine, pestilence and earthquake. The air would grow dark and a dreadful voice would be heard that would destroy the hearts of men. Coastal towns would be covered with sand and earth. All this would be triggered by a rare conjunction of the planets in the sign of the Scales and in the tail of the Dragon. People were advised to flee their homes and find safety in the mountains.
The letter caused panic throughout Europe. The Archbishop of Canterbury ordered a 3-day fast to prevent the calamity. When September 1186 arrived, the planetary conjunction did occur on schedule, but the end of the world never happened.

Gaster, M. (Feb 1902). The Letter of Toledo. Folklore. 13: 115-134.