Little as he deemed there was to fear from this ascetic, the Egyptian Governor-General Raouf, Gordon's successor, and stigmatised by him as the Tyrant of Harrar, became curious about him, and sent someone to interview and report upon this new religious teacher. The report brought back was that he was "a madman," and it was at once considered safe to treat him with indifference. Such was the position in the year 1880, and the official view was only modified a year later by the receipt of information that the gathering on the island of Abba had considerably increased, and that Mahomed Ahmed was attended by an armed escort, who stood in his presence with drawn swords. It was at this time too that he began to declare that he had a divine mission, and took unto himself the style of Mahdi—the long-expected messenger who was to raise up Islam—at first secretly among his chosen friends, but not so secretly that news of his bold step did not reach the ears of Raouf. The assumption of such a title, which placed its holder above and beyond the reach of such ordinary commands as are conveyed in the edicts of a Khedive or a Sultan, convinced Raouf that the time had come to put an end to these pretensions. That conviction was not diminished when Mahomed Ahmed made a tour through Kordofan, spreading a knowledge of his name and intentions, and undoubtedly winning over many adherents to his cause. On his return to Abba he found a summons from the Governor-General to come to Khartoum. That summons was followed by the arrival of a steamer, the captain of which had orders to capture the False Mahdi alive or dead.

Mahomed Ahmed received warning from his friends and sympathisers that if he went to Khartoum he might consider himself a dead man. He probably never had the least intention of going there, and what he had seen of the state of feeling in the Soudan, where the authority of the Khedive was neither popular nor firmly established, rendered him more inclined to defy the Egyptians. When the delegate of Raouf Pasha therefore appeared before him, Mahomed Ahmed was surrounded by such an armed force as precluded the possibility of a violent seizure of his person, and when he resorted to argument to induce him to come to Khartoum, Mahomed Ahmed, throwing off the mask, and standing forth in the self-imposed character of Mahdi, exclaimed: "By the grace of God and His Prophet I am the master of this country, and never shall I go to Khartoum to justify myself."

After this picturesque defiance it only remained for him and the Egyptians to prove which was the stronger.

It must be admitted that Raouf at once recognised the gravity of the affair, and without delay he sent a small force on Gordon's old steamer, the Ismailia, to bring Mahomed Ahmed to reason. This was in August 1881. By its numbers and the superior armament of the troops this expedition should have proved a complete success, and a competent commander would have strangled the Mahdist phenomenon at its birth. Unfortunately the Egyptian officers were grossly incompetent, and divided among themselves. They attempted a night attack, and as they were quite ignorant of the locality, it is not surprising that they fell into the very trap they thought to set for their opponents.

In the confusion the divided Egyptian forces fired upon each other, and the Mahdists with their swords and short stabbing spears completed the rest. Of two whole companies of troops only a handful escaped by swimming to the steamer, which returned to Khartoum with the news of this defeat. Even this reverse was very far from ensuring the triumph of Mahomed Ahmed, or the downfall of the Egyptian power; and, indeed, the possession of steamers and the consequent command of the Nile navigation rendered it extremely doubtful whether he could long hold his own on the island of Abba. He thought so himself, and, gathering his forces together, marched to the western districts of Kordofan, where, at Jebel Gedir, he established his headquarters. A special reason made him select that place, for it is believed by Mahommedans that the Mahdi will first appear at Jebel Masa in North Africa, and Mahomed Ahmed had no scruple in declaring that the two places were the same. To complete the resemblance he changed with autocratic pleasure the name Jebel Gedir into Jebel Masa.

During this march several attempts were made to capture him by the local garrisons, but they were all undertaken in such a half-hearted manner, and so badly carried out, that the Mahdi was never in any danger, and his reputation was raised by the failure of the Government.

Once established at Jebel Gedir the Mahdi began to organise his forces on a larger scale, and to formulate a policy that would be likely to bring all the tribes of the Soudan to his side. While thus employed Rashed Bey, Governor of Fashoda, resolved to attack him. Rashed is entitled to the credit of seeing that the time demanded a signal, and if possible, a decisive blow, but he is to be censured for the carelessness and over-confidence he displayed in carrying out his scheme. Although he had a strong force he should have known that the Mahdi's followers were now numbered by the thousand, and that he was an active and enterprising foe. But he neglected the most simple precautions, and showed that he had no military skill. The Mahdi fell upon him during his march, killed him, his chief officers, and 1400 men, and the small body that escaped bore testimony to the formidable character of the victor's fighting power. This battle was fought on 9th December 1881, and the end of that year therefore beheld the firm establishment of the Mahdi's power in a considerable part of the Soudan; but even then the superiority of the Egyptian resources was so marked and incontestable that, properly handled, they should have sufficed to speedily overwhelm him.

At this juncture Raouf was succeeded as Governor-General by Abd-el-Kader Pasha, who had held the same post before Gordon, and who had gained something of a reputation from the conquest of Darfour, in conjunction with Zebehr. At least he ought to have known the Soudan, but the dangers which had been clear to the eye of Gordon were concealed from him and his colleagues. Still, the first task he set himself—and indeed it was the justification of his re-appointment—was to retrieve the disaster to Rashed, and to destroy the Mahdi's power. He therefore collected a force of not less than 4000 men, chiefly trained infantry, and he entrusted the command to Yusuf Pasha, a brave officer, who had distinguished himself under Gessi in the war with Suleiman. This force left Khartoum in March 1882, but it did not begin its inland march from the Nile until the end of May, when it had been increased by at least 2000 irregular levies raised in Kordofan. Unfortunately, Yusuf was just as over-confident as Rashed had been. He neglected all precautions, and derided the counsel of those who warned him that the Mahdi's followers might prove a match for his well-armed and well-drilled troops. After a ten days' march he reached the neighbourhood of the Mahdi's position, and he was already counting on a great victory, when, at dawn of day on 7th June, he was himself surprised by his opponent in a camp that he had ostentatiously refused to fortify in the smallest degree. The Egyptian force was annihilated. Some of the local irregulars escaped, but of the regular troops and their commanders not one. This decisive victory not merely confirmed the reputation of the Mahdi, and made most people in the Soudan believe that he was really a heaven-sent champion, but it also exposed the inferiority of the Government troops and the Khedive's commanders.

The defeat of Yusuf may be said to have been decisive so far as the active forces of the Khedive in the field were concerned, but the towns held out, and El Obeid, the capital of Kordofan, in particular defied all the Mahdi's efforts to take it. The possession of this and other strong places furnished the supporters of the Government with a reasonable hope that on the arrival of fresh troops the ground lost might be recovered, and an end put to what threatened to become a formidable rebellion. A lull consequently ensued in the struggle. Unfortunately, it was one that the Mahdi turned to the best advantage by drilling and arming his troops, and summoning levies from the more distant parts of the provinces, while the Khedive's Government, engrossed in troubles nearer home—the Arabi revolt and the intervention of England in the internal administration—seemed paralysed in its efforts to restore its authority over the Soudan, which at that moment would have been comparatively easy. The only direct result of Yusuf's defeat in June 1882 was that two of the Black regiments were sent up to Khartoum, and as their allegiance to the Government was already shaken, their presence, as Gordon apprehended, was calculated to aggravate rather than to improve the situation.

Matters remained very much in this state until the Mahdi's capture of the important town of El Obeid. Notwithstanding the presence within the walls of an element favourable to the Mahdi, the Commandant, Said Pasha, made a valiant and protracted defence. He successfully repelled all the Mahdi's attempts to take the place by storm, but he had to succumb to famine after all the privations of a five months' siege. If there had been other men like Said Pasha, especially at Khartoum, the power of the Mahdi would never have risen to the height it attained. The capture of an important place like El Obeid did more for the spread of the Mahdi's reputation and power than the several victories he had gained in the field. This important event took place in January 1883. Abd-el-Kader was then removed from the Governor-Generalship, and a successor found in Alla-ed-din, a man of supposed energy and resource. More than that, an English officer—Colonel Hicks—was given the military command, and it was decided to despatch an expedition of sufficient strength, as it was thought, to crush the Mahdi at one blow.