intended as a visual symbol of his growing authority as caliph, and may have been aimed at defying the rival Fatimid Caliphate to the east which eschewed such structures. Abd ar-Rahman III also reinforced the northern wall of the courtyard by adding another "façade" in front of the old one on the courtyard side. Historical accounts differ on whether the completed courtyard had a surrounding gallery or portico (as seen today and as was common in the courtyards of other mosques). Many modern scholars affirm that the courtyard was provided with an enveloping gallery at this time and that its design involved an alternation between piers and columns (similar to its current appearance). The new works, including the minaret, were completed in 958, as recorded by a surviving inscription on a marble plaque that includes the name of Abd ar-Rahman III as well as the names of the master builder and the supervisor of works. Abd ar-Rahman III's son and successor, Al-Hakam II (r. 961–976), was a cultured man who was involved in his father's architectural projects. During his own reign, starting in 961, he further expanded the mosque's prayer hall. The hall was extended 45 meters to the south by adding 12 more bays (arches), again repeating the double-tiered arches of the original design. This expansion is responsible for some of the mosque's most significant architectural flourishes and innovations. At the beginning of al-Hakam's extension, the central "nave" of the mosque was highlighted with an elaborate ribbed dome (now part of the Capilla da Villaviciosa). More famously, a rectangular maqsura area around the mosque's new mihrab was distinguished by a set of unique interlacing multifoil arches. The rectangular area within this, in front of the mihrab, was covered by three more decorative ribbed domes. The domes and the new mihrab niche were finished in November or December 965, and an inscription records the names of four of its craftsmen who also worked at the Reception Hall (Salon Rico) of Madinat al-Zahra. Soon after this date both the middle dome of the maqsura and the wall surfaces around the mihrab were covered in rich Byzantine-influenced gold mosaics. According to traditional accounts like that of Ibn 'Idhari, Al-Hakam II had written to the Byzantine emperor (initially Nikephoros II Phokas) in Constantinople requesting that he send him expert mosaicists for the task. The emperor consented and sent him a master craftsman along