The siege of Algeciras was a battle of the Spanish Reconquista that occurred between July 1309 and January 1310. The battle was fought between the forces of the Kingdom of Castile, commanded by King Ferdinand IV of Castile and his vassals, and the Emirate of Granada commanded by Sultan Abu'l-Juyush Nasr. The battle resulted in a humiliating defeat for the Kingdom of Castile whose army was obliged to lift the siege due to the atrocious conditions of life in the Castilian camp and the desertion of Infante John of Castile. The battle marked one of the many battles fought at Algeciras where the Christian forces would try to take the city unsuccessfully from the Muslims.