http://quicksilver899.com/Bible_Mysteries/Great_Delusion/Delusion5.html
In its chronology of the years, for 1561 Wikipedia lists an odd entry for April 14: 'The citizens of Nuremberg see what appears to be an aerial battle followed by the appearance of a large black triangular object and a large crash (with smoke) outside the city. A news notice (early form of newspaper) was printed 10 days later (April 14) describing the event1|.'
. 
Image taken from news 'broadsheet' at Nuremberg, Germany, in April, 1561.
Some have explained the phenomenon as a 'sundog' - ice crystals reflecting sunlight. It is not clear if this explanation would account for the large black 'triangle'.
The incident seems to have come to modern attention in C. G. Jung's 'Flying Saucers: A Modern Myth of Things Seen in the Skies'.
(many thanks to Bob Ireland)