preserved and repeated the original design while extending the prayer hall eight bays to the south (i.e. the length of eight arches). This made the prayer hall 64 metres long from front to back. During this expansion, the builders began to commission new marble capitals for the columns instead of just re-using ancient ones. These new capitals were imitations of the Corinthian style but still differed slightly from classical models, thus hinting at the future evolution of architectural sculpture in al-Andalus. One probable example of these capitals is now preserved at the National Archaeological Museum in Madrid and features an Arabic inscription in an archaic Kufic script that offers blessings on Abd ar-Rahman II. The expansion work may have been unfinished when Abd ar-Rahman II died in 852 and it appears to have been completed instead by his son and successor, Muhammad I (r. 852–886). Muhammad I carried out various other works on the mosque and is reported to have created a maqsura (a prayer space reserved for the ruler). In 855 he also restored the Bab al-Wuzara gate (today's Puerta de San Esteban). The decoration of this gate, which thus likely dates from this time, is often noted as an important prototype of later Moorish gateways. Muhammad's son, Al-Mundhir (r. 886–888), in turn added a treasury to the mosque. Al-Mundhir's son, Abdallah (r. 888–912), built the mosque's first elevated passage, known as a sabat, which connected the mosque directly with the Umayyad palace across the street. This passage allowed the ruler thenceforth to enter the mosque privately, where he would remain unseen behind the screen of the maqsura, thus separating him from the general public during prayer. (New versions of this bridge would later be rebuilt during the mosque's subsequent expansions.) In the 10th century Abd ar-Rahman III (r. 912–961) declared a new Caliphate in al-Andalus and inaugurated the height of Andalusi power in the region. As part of his various construction projects, he reworked and enlarged the courtyard of the Great Mosque and built its first true minaret (a tower from which the call to prayer was issued) starting in 951–952. The minaret was 47 meters high and had a square base measuring 8.5 meters per side. Scholar Jonathan Bloom has suggested that Abd ar-Rahman III's construction of the minaret – along with his sponsoring of other minarets around the same time in Fez, Morocco – was partly