The attitude of Abd-er-Rahman I. towards the Christian population of Cordova was, therefore, clement and conciliatory. Under his sovereignty there dawned an age of prosperity and advancement. The work of building the resplendent Mezquita employed thousands of artisans and labourers. This vast undertaking led to the development of all the resources of the district. Durable stone and beautifully veined marbles were quarried from the Sierra Morena and the surrounding regions of the city. Metals of various kinds were dug from the soil, and factories sprang up in Cordova amid the stir and bustle of an awakened industrial energy. A famous Syrian architect made the plans for the Mosque. Leaving his suburban dwelling, the Khalif came to reside in the city, so that he might personally superintend the operations, and offer proposals for the improvement of the designs. We are told that Abd-er-Rahman moved about among the workers, directing them during several hours of every day. The monarch was growing old. It was the longing of his heart to witness the final achievement of his great scheme before death overtook him. In planning the Mosque the architects incorporated a number of Roman columns with choice capitals. Some of the columns were already in the Gothic structure; others were sent from various quarters of Spain as presents from the governors of provinces. Ivory, jasper, porphyry, gold, silver, copper, and brass were used in the decorations. Marvellous mosaics and azulejos were designed. Panels of scented woods were fastened with nails of pure gold, and the red marble columns were said to be the work of God. The primitive part of the building, reared under the direction of Abd-er-Rahman I., was that bordering the Court of Oranges. Later, the immense temple embodied all the styles of Morisco architecture in one noble composition. The first Khalif of Cordova did not survive to witness the completion of the Mosque. He died in the Alcazar long before the work was finished, and committed the task to his son Hisham. The prince carried on the work with zealous devotion. Upon his father’s death in 788, the building covered only a small part of the ground now occupied by the Mosque and its later additions. Hisham I. built the tower for the muezzin, and the fretted gallery for the women worshippers, and added much to the Zeca, or House of Purification, erected by Abd-er-Rahman.