0547 (ca.): The Plague of Justinian
According to a history written in 1721, some strange events occurred during the bubonic plague that raged through the Byzantine Empire from 541~550 CE, a plague that has been named after Justinian I [ca. 482-565], who was emperor when the plague broke out, and who also caught and -- surprisingly -- survived the disease himself.
The Byzantine Empire stretched from Egypt in the South to Italy in the North; and around the year 547 CE, it's stated that small boats were reportedly seen by people out at sea that contained black men without heads. These boats were said to have originated in Egypt in the Gaza region; when they sailed past the village of Serri, disease began to attack them. These boats were associated with outbreaks throughout the empire.
Reported by the same history as presumably happening about the same time is a curious story from Egypt. In an unnamed city in Egypt that was full of pestilence, a ten-year-old boy and seven men were gathering up a huge amount of gold and silver from the abandoned houses when, suddenly, the seven men all fell dead. Alarmed, the boy fled the house, leaving the wealth behind, but when he came to the gates of the city he was returned to the house in which the men had perished by a "spectro" -- which is Latin for 'spectrum,' but has been rendered by some translators as 'specter'. In any case, the boy was returned to the house and could not leave. Sometime afterwards, the steward of one of the wealthiest men in the city arrived with servants at the house to retrieve furniture left behind. Seeing the steward, the boy immediately tried to warn him away from the house and the city, but the 'spectro' returned and both died of the pestilence instantly... leaving the servants to report the tale back to their master.
My Source's Source
The author of this history refers to another author -- Joannes -- as his source for the details above. This is likely a reference to a text that was mentioned earlier in the same book, so I will try to track backwards through the Latin to find what this earlier source was.