The building was carried on with incredible activity during the whole of his reign, for the Sultan begrudged no expenditure that could add to its magnificence; yet it was not until nine years after the death of Abd-er-Rahman that the Mosque was completed according to the original plan. The design was accomplished by the Sultan Hisham I. in the years 794-5, and the Mosque received considerable improvements at the hands of his successors; indeed, it can be safely said that none of the Sultans of the illustrious family of Omeyyah who reigned in Cordova failed to make some estimable addition, or contributed in some way to the decoration of the sumptuous building. Hisham’s son, Abd-er-Rahman II. (A.D. 822-852), ordered much ‘gilt work’ (_Zak-hrafah_) to be made, but died before the work was carried out. Mohammed, his son and successor (A.D. 852-886), continued the work begun by his father, and brought it to a close. Mohammed’s son, Mundhir, in a short reign (A.D. 886-888), is recorded as having made improvements in the building. The great Khalif, An-nassir (Abd-er-Rahman III., A.D. 912-961), caused the old minaret to be pulled down and a more magnificent one to be erected. Al-hakem Al-mustanser-billah (Hakem II., A.D. 961-976) made important additions. Seeing, on his accession, that Cordova was every day increasing in extent, and the population rapidly growing, he directed his attention to the enlargement of the Mosque, and completed the additional building known by his name, by which the structure, already gorgeous, reached the highest perfection, the work of his time being executed in a manner that bewilders by its excellence. Lastly, in the reign of his successor Hisham II. (A.D. 976-1009), and under the administration of his famous _Hajib_ (Lord Chamberlain and Prime Minister) Al-Mansur, or Almanzor, as he is more commonly called, an addition was made which almost doubled the capacity of the building. A vast number of houses were pulled down, the sites and the lands belonging to them appropriated for the extension of the Mosque; the addition falling nowise short, in respect of solidity, beauty of design, and boldness of execution, of those of any of his predecessors, unless we except the transcendent work of Hakem II. The grace and purity of construction and decoration in Cordova reached their zenith during the reign of Hakem II. He it was who built the _maksurrah_[3] within the Mosque, a production that has been described by contemporary writers as one of the most exquisite fabrics ever raised by man. In the two jambs of the arch forming the entrance to the _mih-rab_[4] were four columns of great value: two were made of green marble, the other two of lapis-lazuli.[5]