This is a study of the two codices of the Biblioteca de Santa Cruz in Valladolid (Spain) containing works by Rodrigo Jiménez de Rada, «el Toledano»; the first, ms. 42, previously studied en the edition of De rebus Hispanie (CC.CM.LXXII), confirms, working from the Historia Arabum, his direct dependence on the ms. B; the second, ms. 54, studied here for the first time, derives from the same codex as Z and (3.