A series of mass sightings of celestial phenomena occurred in 1566 above Basel, Switzerland. The Basel pamphlet of 1566 describes unusual sunrises and sunsets. Celestial phenomena were said to have "fought" together in the form of numerous red and black balls in the sky before the rising sun. The report is discussed among historians and meteorologists. The phenomenon has been interpreted by some ufologists to be a sky battle between unidentified flying objects. The leaflet written by historian Samuel Coccius reported it as a religious event. The Basel pamphlet of 1566 is not the only one of its kind. In the 15th and 16th centuries, many leaflets wrote of "miracles" and "sky spectacles".