Modern Seville is a city of the Renaissance – the most Italian of Spanish cities, said a Venetian ambassador in the 16th century – and above all a city of the baroque, a style which may be regarded as the antithesis of traditional Islamic taste. Yet the symbol of Seville, endlessly reproduced on everything from key chains to cookie boxes, is the Giralda: once the minaret of a huge congregational mosque, now the bell tower of Europe's third-largest cathedral. The Giralda dates back to the brief period between 1147 and 1229 when Ishbiliyah, as the city was known to the Arabs, was ruled by the North African Muslim dynasty called the Almohads (al-Muwahhidun), and under them became the capital of al-Andalus.
A great deal is known about the building of this mosque and its minarets, thanks to the chance survival of the second volume of a three-volume history of the Almohad dynasty entitled al-Mann bil-Imamah (The Gift to the Imamate). The author, Ibn Sahib al-Sala, was in the service of Almohad caliph Abu Ya'qub Yusuf and witnessed many of the events he describes. The manuscript, discovered in the Bodleian Library in Oxford in 1930, gives precious details of the caliph's building projects, including the names of the architects he used.
The chief architect of the mosque, and the man who laid the foundation of the minaret, was Ahmad ibn Basu. Ibn Sahib al-Sala says that in April 1172 "the Commander of the Faithful began to mark out the site of this noble and beautiful mosque. The houses near the gate of the palace precinct were demolished and the project put into the hands of the chief architect, Ahmad ibn Basu, and his colleagues, the architects and masons of Ishbiliyah. They were aided by all the other builders in al-Andalus, as well as those of Marrakech and Fez and other cities across the Strait [of Gibraltar]. They all came to Seville, along with various sorts of carpenters and sawyers and other craftsmen in great numbers, each with his own specialty."
The work went on for three years and 11 months, with the caliph personally supervising the project and visiting the site almost every day. When the huge mosque – as big as that in Córdoba – was finished and roofed, Yusuf was called back to his North African capital, Marrakech. Eight years passed before he returned to Seville.
When he did so, in 1184, it was to attack the well-defended Christian stronghold of Santarem. On the eve of this campaign, Yusuf ordered Seville's governor to build a minaret for the new mosque, but he did not live to see it. The caliph was killed in the Battle of Santarem and his son, al-Mansur, succeeded him.
Al-Mansur scrupulously carried out his father's last wish. Once again, Ahmad ibn Basu was named chief architect. He dug deep against the wall of the mosque and at a great depth discovered a spring, perhaps used in Roman times to supply water to the city. He blocked the spring with stone and laid the minaret's foundation above it. This must have been a long and difficult job, but one well done: The minaret has stood for eight centuries and survived a number of earthquakes.
Stones from the walls of an old palace nearby were used for the foundation. Some of these stones dated back to Visigothic or even Roman times, used and re-used in successive buildings. Two Roman dedication tablets, originally set up by an organization of sailors in the Roman town, are still visible at the base of the structure, and may have been placed there by the architect as a symbol of Islam's triumph over Roman lands.
When the base of the tower had risen a few meters above ground, work suddenly ceased. Ibn Basu may have died, for when work recommenced in 1188, a new architect, 'Ali al-Ghumari, was in charge. Al-Ghumari decided to use baked brick instead of cut stone for the rest of the minaret, and the point of transition can still be clearly seen.
Unable to oversee the work personally, al-Mansur sent his trusted advisor, the famous physician and poet Abu Bakr ibn Zuhr – known in the Latin Middle Ages as Avenzoar – from Marrakech to supervise the project. Thus the Giralda is linked to one of the most famous names in Islamic Seville.
The outer surface of the minaret was decorated with a pattern of interlaced arches in raised brickwork, and glass panes were set in the windows. Access to the top was by a series of 34 gently sloping ramps. The central core consisted of seven rooms, probably used for storage or as quarters for guards, for the minaret also served as a watchtower.