The Siege of Algeciras was the first of many sieges on the city by Christian forces in the lengthy period of Spanish Reconquista. The siege, ordered by King Alfonso X of Castile also known as "el Sabio", was a fruitless military campaign initiated by the Kingdom of Castile with the objective of removing the Moroccans from Algeciras. The siege on Algeciras, then known to the Muslims as Al-Jazira Al-Khadra, was strategically important because Algeciras had been at the time the main fortress and landing place for African reinforcement troops in the Iberian Peninsula. Castile, which had a powerful armada of ships anchored in the Bay of Gibraltar to blockade such reinforcement, had a few days previously to the siege, seen that fleet obliterated by the Muslim admiral, Abu Yusuf Yaqub at the Nava