The tower was built in the 9th century under the rule of Abd al-Rahman II. It belonged to one of the numerous medieval mosques that existed at Umayyad time throughout the different quarters of the city. As a minaret (that’s a tower built into a mosque), its main function was that from the top, the muezzin called the faithful to prayer five times a day. Its height must have been greater than the current 11 metres and culminated in a lantern on a terrace with battlements, in the style of the main minarets of Al-Andalus. It is actually only the first section that’s been preserved. After taking the city in 1236, King Ferdinand III donated several mosques of the city to both religious and military orders, and noblemen that helped him conquer the city. The Knights of St. John of Jerusalem – San Juan de los Caballeros - became the new owners of the site, transforming the mosque into a church and its minaret into a belfry.