Before the close of the eighteenth century the chiefs of the Ibn Saouds, champions of Unitarian Islam, had established their authority over all Northern Arabia as far as the Euphrates, and in 1808 they took Mecca and Medina. In the meanwhile the Wahhabite doctrines were gaining ground still further afield. India was at one time very near conversion, and in Egypt, and North Africa, and even in Turkey many secretly subscribed to the new doctrines. Two things, however, marred the plan of general reform and prevented its full accomplishment. In the first place the reform was too completely reactive. It took no account whatever of the progress of modern thought, and directly it attempted to leave Arabia it found itself face to face with difficulties which only political as well as religious success could overcome. It was impossible, except by force of arms, to Arabianise the world again, and nothing less than this was in contemplation. Its second mistake, and that was one that a little of the Prophet's prudence which always went hand in hand with his zeal might have avoided, was a too rigid insistance upon trifles. Abd el Wahhab condemned minarets and tombstones because neither were in use during the first years of Islam. The minarets therefore were everywhere thrown down, and when the holy places of Hejaz fell into the hands of his followers the tombs of saints which had for centuries been revered as objects of pilgrimage were levelled to the ground. Even the Prophet's tomb at Medina was laid waste and the treasures it contained distributed among the soldiers of Ibn Saoud. This roused the indignation of all Islam, and turned the tide of the Wahhabite fortunes. Respectable feeling which had hitherto been on their side now declared itself against them, and they never after regained their position as moral and social reformers. Politically, too, it was the cause of their ruin. The outside Mussulman world, looking upon them as sacrilegious barbarians, was afraid to visit Mecca, and the pilgrimage declined so rapidly that the Hejazi became alarmed. The source of their revenue they found cut off, and it seemed on the point of ceasing altogether. Then they appealed to Constantinople, urging the Sultan to vindicate his claim to be protector of the holy places. What followed is well known. After the peace of Paris Sultan Mahmud commissioned Mehemet Ali to deliver Mecca and Medina from the Wahhabite heretics, and this he in time effected. The war was carried into Nejd; Deriyeh, their capital, was sacked, and Ibn Saoud himself taken prisoner and decapitated in front of St. Sophia's at Constantinople. The movement of reform in Islam was thus put back for, perhaps, another hundred years.