Discovery of an 11th-century geometrical compilation: the Istikmāl of Yūsuf al-Mu'taman ibn Hūd, King of Saragossa (Q1071742)

This Istikmal is a book highly valued by medieval Arabic bibliographers. It was assumed to be lost until the present paper announced that a large part of it survived in four anonymous manuscripts. The author gives convincing evidence of identification, together with a description of the contents based on the extant material. The work is an intelligent thematical, mainly geometrical compilation of material derived from Euclid, Apollonius, Archimede and several others.