ABSTRACT
Abº ‘Æmir Yºsuf ibn Hºd AÌmad ibn Hºd, known as al-Mu’taman,1 succeeded his father as King of Saragossa on the death of the former in 474/1081. His reign was not to be a long one, as al-Mu’taman died four years later in 478/1085.2 The King is credited with the authorship of the
substantial mathematical work, the Istikmæl,3 which he appears to have composed while still the Crown Prince. The wide range of topics covered by the book, together with its bulk, all suggest that it represents the sum total of a life devoted to mathematics. It could not possibly have been written during the few leisurely hours available to a king, regardless of the true extent of his kingdom. We must therefore consider him to have been a mathematical crown prince rather than a mathematical king, much as we would prefer to imagine the latter.
