The Battle of Jerez () took place in 1231 near the southern Spanish city of Jerez de la Frontera during the Reconquista. King Ferdinand III of Castile and León's troops fought against those of Emir Ibn Hud of the taifa of Murcia. The Castilian forces were led by Ferdinand's brother, Prince Alfonso de Molina, assisted by Álvaro Pérez de Castro; according to some accounts Castro led the Castilians, not Molina. The battle is traditionally seen as marking the collapse of Ibn Hud's authority, and allowing the rise of his successor, Muhammad I. Battle In April 1231, King Ferdinand III of Castile and León ordered an expedition by algaras (mounted raiders). This departed from Andújar towards Córdoba, leaving a trail of destruction in its path. They raided Palma del Río, killing many inhabitants, then proceeded as far as Seville which they bypassed. The expedition proceeded towards Jerez and Vejer camping near the Guadalete River. In all likelihood this force was intended to distract Ibn Hud from the frontier, and in this it succeeded. Emir Ibn Hud pursued and caught the expedition, but in the subsequent battle his troops were routed and suffered heavy losses, allowing the Christians to depart loaded with loot. On a strategic level, the raid was also successful in that it allowed the unimpeded capture of Quesada by an army of Archbishop Rodrigo Jiménez de Rada, also ordered in April by Ferdinand. Castilian commander It is not clear who led the Castilian expedition. It is undisputed that Álvaro Pérez de Castro was present, and he may have been in command. A reference to infante Alfonso in the Christian chronicle has been interpreted to mean either the King's brother, Alfonso de Molina, or the King's son, the future Alfonso X. The Primera Crónica General (1906) interpreted it as Molina, and so did historian in 1978. However, historian concluded in 2000 that it was the king's son, because of a passage that describes the infante as being very young ("muy moço") and under the protection of Álvaro Pérez de Castro who led the troops ("para guardar el infante y por cabdillo de la hueste"). Spanish historian was aware of both interpretations, but in 1946 thought it was highly improbable that Ferdinand's son was involved in a military action at such a young age. A 2003 biography of Alfonso X also places him alongside Álvaro Pérez de Castro in the raiding