Abu al-Saqr Abd al-Aziz Ibn Uthman Ibn Ali al-Qabisi (known in Latin as Alcabitius, died 967), was a famous Arab astrologer and mathematician who lived in the palace of Saif Al-Dawla Al-Hamdani in Aleppo, Syria. He is best known for his Introduction to the Art of Judgments of the Stars, a treatise on judicial astrology or the forecasting of events from the positions of planets and stars. The book was translated into Latin in the 12th century by Johannes Hispalensis and was highly prized in medieval Europe for its astrological lore. A revised translation into Latin was made in the 13th century. The first Latin printed edition appeared in 1473. Shown here is the edition of 1512, published in Venice by the printer Melchiorre Sessa, identifiable by his printer’s mark: the initials “MS” beside a crown above the image of a cat that has just caught a mouse. The edition includes a 14th-century commentary on Alcabitius by John Danko of Saxony (active, 1327–55), an astronomer at the University of Paris. Danko was also known for his important revisions to the Alfonsine Tables based on the work of the 11th-century Arab astronomer Ibrahim Ibn Yahya an-Nakash al-Zarqali (Latinized as Arzachel).