Andalusian astronomer of the 12th century (he died ca. 1204 CE). Born in present-day Morocco, he settled in Seville, and became a disciple of Ibn Tufayl and was a contemporary of Ibn Rushd.
He wrote a Kitab al-hay'a that was translated into Hebrew, and then into Latin (printed in Vienna in 1531). In this book, he advanced a theory on planetary motion in which he wished to avoid both epicycles and eccentrics, and to account for the phenomena peculiar to the wandering stars, by compounding rotations of homocentric spheres. This was a modification of the system of planetary motion proposed by his predecessors, Ibn Bajjah (Avempace) and Ibn Tufayl. But his efforts were unsuccessful in replacing Ptolemy's planetary model, due to the numerical predictions of the planetary positions in his configuration being less accurate than that of the Ptolemaic model, mainly because he followed Aristotle's notion of perfect circular motion.
See Osman Bakar, "The Golden Age of Andalusian Science".