Guido Bonatti (died between 1296 and 1300) was an Italian mathematician, astronomer and astrologer, who was the most celebrated astrologer of the 13th century.  He is probably the first astrologer to have used the midpoints in astrology. He used it to refine the timing for the military campaigns for the Count of Montefeltro. Bonati announced to the count that he would repulse the enemy but would be wounded in the fray. The event transpired as Bonati had predicted, and the count, who had taken with him the necessary materials to staunch his wound in case the prophecy came true, became a devout adherent of astrology.