Ali ibn Abderrahmen ibn Hudhayl (or Hodeil) al-Andalusi lived in the Nasrid sultanate of Granada (now southern Spain) in the second half of the fourteenth century. He wrote a treatise on the art of war, horsemanship and the handling of weapons on horseback for the sultan Muhammad V, who reigned between 1354 and 1362 AD. For the sultan Muhammad VII, who reigned between 1370 and 1408, he later revised his treatise, cutting out the first twenty chapters, which cover the art of war from a general perspective.
The final chapters are the ones of most interest to historical martial artists. They contain practical advice on learning to use the bow, the lance, the sword and the shield on horseback.
The first half of the treatise, dealing with the art of war, was edited and translated into French by Louis Mercier under the title L'ornament des âmes et la devise des habitants d'el Andalus : traité de guerre sainte islamique (Paris: P. Geuthner, 1939).
The second half of the treatise, dealing with horses, horsemanship and weapons-handling, was also edited by Louis Mercier. His edition of the original Arabic text is out of copyright and may be found online here: http://www.archive.org/stream/laparuredescaval00ibnh#page/n115/mode/2up.
Mercier also translated this second half of the treatise into French under the title La parure des cavaliers et l'insigne des preux (Paris: P. Geuthner, 1924). It is not yet online. Mercier's translation should be treated with caution, as every Arabist who quotes him seems to correct a word or two.
There is also a Spanish translation of the treatise, by M. J. Viguera, under the title Gala de Caballeros, Blasón de Paladines (Madrid: Editora Nacional, 1977).
Excerpts in English, based on Mercier's French translation (and thus probably somewhat corrupt), may be found in this thread: http://www.fioredeiliberi.org/phpBB3/viewtopic.php?f=4&t=18371.
Large parts of ibn Hudhayl's treatise are probably unattributed borrowings from much earlier Arab writers, but since most Islamic chivalric literature has yet to be edited or published in any language, it is difficult to know what texts he used for sources.