This religious reformer and adventurer styled himself "Abu Gemaizeh" (Gemaizeh is the Arabic name for the sycamore fig-tree), because it was said that the shade of this tree always accompanied him. At Omdurman all sorts of extraordinary stories were current about his supernatural gifts. Some said that he had the power of miraculously increasing food; an ordinary plate-full he would make sufficient for hundreds of people; others said that they had seen him produce milk from his finger-tips, and it was said that he could produce, in a moment, all sorts of things pleasant to the palate. He could raise a palm-tree out of barren ground, which, in the space of an hour, would become covered with fruit. In his sermons and letters he reproached the Khalifa for having oppressed and slaughtered Moslems, and having taken their wives for himself—a crime only committed by the "unbelievers"—and with God's help, he declared his intention of coming to Omdurman to annihilate "God's enemies," as he called the Dervishes.
The sayings and doings of this extraordinary being attracted great attention throughout the entire Sudan. The Mahdi had first appeared in the west, and now an anti-Mahdi had sprung up from the west. Immense numbers of adherents flocked to his standard. Not only did the Furs, thirsting for vengeance, join him, but people from Bornu, Borgo, and Wadai collected around him.
Osman Wad Adam despatched a force against him, which was annihilated, and he now begged the Khalifa to send him reinforcements. In answer to this appeal a number of Beni Jerrar Arabs were sent to him, but these also were destroyed almost to a man. These two important victories increased Abu Gemaizeh's prestige enormously, and when Abdullah saw that the oppressed Sudanese were secretly rejoicing at his discomfiture, he himself began to tremble for his authority.
A third expedition, despatched by Osman, met with a similar fate to the other two, and now the Khalifa vented his wrath on his unsuccessful lieutenant. In October 1888, he wrote to him to retire at once to El Fasher, to confine himself entirely to defensive operations, and on no account to attack the enemy. There was great excitement in Omdurman, where the importance of Abu Gemaizeh's victories had been enormously exaggerated. It was even said that Osman had been killed, El Fasher captured, and Kordofan on the point of being invaded. Then came the news that El Obeid had been captured, and now the rejoicings at the Khalifa's defeat were an open secret. But these highly-coloured rumours were merely the outcome of an intense desire and longing on the part of the wretched inhabitants of the Sudan, groaning under the Dervish yoke, to see themselves once more free from the tyrannical oppression which their own short-sighted conduct had brought upon themselves.
Abu Gemaizeh had, it is true, been very successful. He had three times defeated Osman, who was now besieged in El Fasher, and in great want of food. All Darfur had sided with Abu Gemaizeh, and the Dervishes were almost powerless; but in the zenith of his success the great religious sheikh was suddenly struck down by small-pox, and died at Kebkebieh in February 1889. His death caused many of his adherents to quit the cause, and his successor—who, had he not attacked El Fasher, might have succeeded in compassing the downfall of Osman, who was then entirely cut off and in great straits—felt that he must do something to keep his army together. But his force was hampered by a large number of women, children, and camp followers. He was deficient in firearms, whilst Osman was well supplied with rifles and ammunition, and his Shaggieh troops fought magnificently.
The final action took place under the walls of El Fasher, on the 22nd of February, 1889, and resulted in the death of the leader and the massacre of thousands of his followers. This was the death-blow to the movement, and is an example of how easily Moslems are imposed upon by religious adventurers. Numbers of those who had joined and left Mahdiism, thoroughly convinced of its fraud and deception, had unhesitatingly allied themselves to this new religious movement, which they inspired with almost greater enthusiasm than that they had just quitted. The collapse of this new delusion was therefore comparatively greater. The heads of Abu Gemaizeh and a number of his important leaders were sent to Omdurman, where they found a place on the gallows, and were subsequently relegated to the pit in which lay the whitening skulls of Merhdi, the Abyssinians, and the mutinous blacks.
Osman's victory delighted the Khalifa even more than Abu Anga's success in Abyssinia, because he had always considered Darfur a place of refuge, to which he had a secure line of retreat in case of attack from the north.
The victorious Osman now vented his wrath on the tribes who had supported Abu Gemaizeh's movement. The Beni Helba tribe especially fell under his merciless hand, and was almost exterminated; but the country took some time to recover its normal state, and, in consequence, the Khalifa had to forego the pleasure of summoning Osman to Omdurman, and loading him with benefits as he had done to Abu Anga. However, he had a special house built for him near the mosque, and prepared to do him all honour when his presence could be spared from Darfur.
But this was not to be. The successful Osman fell ill, and died shortly afterwards at El Fasher. He was succeeded by the Khalifa's brother Mahmud Wad Ahmed, who was also accompanied by the kadi Suleiman el Hejazi. This latter individual was deported to Darfur because he had had a disagreement with the Khalifa's principal spy, Hajji Zubeir.
Mahmud was ordered, on his arrival at El Fasher, to send to Omdurman all the money found in the late Osman's safe, and to take over all his horses, wives, &c., and keep them for himself. He left Omdurman with a large number of followers, and travelling viâ El Obeid at length reached his province. Here he found the country desolate; during the recent wars all cultivation had lapsed, a terrible famine had set in, and he was unable to find food for his troops. On reporting this to the Khalifa, he received orders to retire to Nahut in Kordofan, which he did, but his black soldiers disliked the change, and conspired together to kill Mahmud and desert back to Darfur. They attempted to carry out this project one night, but failing to secure the ammunition, which was essential to the success of their undertaking, they deserted from the camp, about 1,000 strong, and set off to join Rabeh Zubeir.