Abstract

It was a strange posthumous fate that awaited the Englishman Robert of Ketton : he was to be both best known and most strenuously criticized for a work that he surely viewed as a sideline to his own interests and career. By trade Robert was a Latin translator of Arabic scientific and mathematical works, one of those remarkable twelfth-century men who, as his contemporary Petrus Alfonsi put it, were willing “to traverse distant provinces and withdraw into remote regions so as to be able to attain fuller knowledge of the astronomical art.” Like other contemporary translators, such as the Italian Gerard of Cremona , Robert had left his birthplace—in his case Rutlandshire—and traveled to Spain in order to have access to the great works of Arabic astronomy and mathematics that could be found in the still very Arab Iberian Peninsula. By 1141 we find him and his close friend Herman of Carinthia studying and translating scientific works together in northeastern Spain, and in later years his astronomical interests and ecclesiastical responsibilities led him to travel widely in Spain and England. As a scientific translator, he is perhaps best known for his Liber algebrae et Almucabola, a Latin version of al-Khwarazmī's great manual of algebra, Al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa-al-muqābalah