It is now known that the Khalifa had succeeded in concentrating at Omdurman an army of more than 60,000 men. He remembered that all the former victories over the Egyptians had been won by the Dervishes attacking. He knew that in all the recent defeats they had stood on the defensive. He therefore determined not to oppose the advance at the Shabluka or on the march thence to Omdurman. All was to be staked on the issue of a great battle on the plains of Kerreri. The Mahdi's prophecy was propitious. The strength of the Dervish army seemed overwhelming. When the 'Turks' arrived, they should be driven into the river. Accordingly the Khalifa had only watched the advance of the Expeditionary Force from Wad Hamed with a patrol of cavalry about 200 strong. On the 30th he was informed that the enemy drew near, and on the 31st he assembled his bodyguard and regular army, with the exception of the men needed for the river batteries, on the Omdurman parade ground. He harangued the leaders; and remained encamped with his troops during the night. The next day all the male population of the city were compelled to join the army in the field, and only the gunners and garrisons on the river-face remained within. In spite, however, of his utmost vigilance, nearly 6,000 men deserted during the nights of the 31st of August and the 1st of September. This and the detachments in the forts reduced the force actually engaged in the battle to 52,000 men. The host that now advanced towards the British and Egyptian cavalry was perhaps 4,000 stronger.
Their array was regular and precise, and, facing northeast, stretched for more than four miles from flank to flank. A strong detachment of the mulazemin or guard was extended in front of the centre. Ali-Wad-Helu, with his bright green flag, prolonged the line to the left; and his 5,000 warriors, chiefly of the Degheim and Kenana tribes, soon began to reach out towards the Egyptian cavalry. The centre and main force of the army was composed of the regular troops, formed in squares under Osman Sheikh-ed-Din and Osman Azrak. This great body comprised 12,000 black riflemen and about 13,000 black and Arab spearmen. In their midst rose the large, dark green flag which the Sheikh-ed-Din had adopted to annoy Ali-Wad-Helu, of whose distinctive emblem he was inordinately jealous. The Khalifa with his own bodyguard, about 2,000 strong, followed the centre. In rear of all marched Yakub with the Black Flag and 13,000 men—nearly all swordsmen and spearmen, who with those extended in front of the army constituted the guard. The right wing was formed by the brigade of the Khalifa Sherif, consisting of 2,000 Danagla tribesmen, whose principal ensign was a broad red flag. Osman Digna, with about 1,700 Hadendoa, guarded the extreme right and the flank nearest Omdurman, and his fame needed no flag. Such was the great army which now moved swiftly towards the watching squadrons; and these, pausing on the sandy ridge, pushed out a fringe of tentative patrols, as if to assure themselves that what they saw was real.
The Egyptian cavalry had meanwhile a somewhat different view of the spectacle. Working on the right of the 21st Lancers, and keeping further from the river, the leading squadrons had reached the extreme western end of the Kerreri ridge at about seven o'clock. From here the Mahdi's Tomb was visible, and, since the rocks of Surgham did not obstruct the view from this point, the British officers, looking through their field-glasses, saw what appeared to be a long column of brown spots moving south-westwards across the wide plain which stretches away to the west of Omdurman. The telescope, an invaluable aid to reconnaissance, developed the picture. The brown objects proved to be troops of horses grazing; and beyond, to the southward, camels and white flapping tents could be distinguished. There were no signs that a retreat was in progress; but from such a distance—nearly four miles—no certain information could be obtained, and Colonel Broadwood decided to advance closer. He accordingly led his whole command south-westward towards a round-topped hill which rose about four miles from the end of the Kerreri ridge and was one of the more distant hill features bounding the plain on the western side. The Egyptian cavalry moved slowly across the desert to this new point of observation. On their way they traversed the end of the Khor Shambat, a long depression which is the natural drainage channel of the plains of Kerreri and Omdurman, and joins the Nile about four miles from the city. The heavy rain of the previous night had made the low ground swampy, and pools of water stood in the soft, wet sand. The passage, however, presented no great difficulty, and at half-past eleven the Egyptian squadrons began to climb the lower slopes of the round-topped hill. Here the whole scene burst suddenly upon them. Scarcely three miles away the Dervish army was advancing with the regularity of parade. The south wind carried the martial sound of horns and drums and—far more menacing—the deep murmur of a multitude to the astonished officers. Like the 21st Lancers—three miles away to their left, at the end of the long sandy ridge which runs westward from Surgham—the soldiers remained for a space spell-bound. But all eyes were soon drawn from the thrilling spectacle of the Dervish advance by the sound of guns on the river.
At about eleven o'clock the gunboats had ascended the Nile, and now engaged the enemy's batteries on both banks. Throughout the day the loud reports of their guns could be heard, and, looking from our position on the ridge, we could see the white vessels steaming slowly forward against the current, under clouds of black smoke from their furnaces and amid other clouds of white smoke from the artillery. The forts, which mounted nearly fifty guns, replied vigorously; but the British aim was accurate and their fire crushing. The embrasures were smashed to bits and many of the Dervish guns dismounted. The rifle trenches which flanked the forts were swept by the Maxim guns. The heavier projectiles, striking the mud walls of the works and houses, dashed the red dust high into the air and scattered destruction around. Despite the tenacity and courage of the Dervish gunners, they were driven from their defences and took refuge among the streets of the city. The great wall of Omdurman was breached in many places, and a large number of unfortunate non-combatants were killed and wounded.
Meanwhile the Arab irregulars, under Major Wortley, had been sharply engaged. That officer's orders were to co-operate with the flotilla by taking in rear the forts and fortified villages on the east bank of the river. As soon as the gunboats had silenced the lower forts, Major Wortley ordered the irregulars to advance on them and on the houses. He placed the Jaalin, who were practically the only trustworthy men in his force, in reserve, and formed the tribes according to their capabilities and prejudices. On the order to attack being given, the whole force, some 3,000 strong, advanced on the buildings, from which the Dervishes at once opened fire. Arrived within 500 yards they halted, and began to discharge their rifles in the air; they also indulged in frantic dances expressive of their fury and valour, but declined to advance any further.
Major Wortley then ordered the Jaalin to attack. These—formed in a long column, animated by the desire for vengeance, and being besides brave men—moved upon the village at a slow pace, and, surrounding one house after another, captured it and slew all its defenders; including the Dervish Emir and 350 of his followers. The Jaalin themselves suffered a loss of about sixty killed and wounded.
The village being captured, and the enemy on the east bank killed or dispersed, the gunboats proceeded to engage the batteries higher up the river. The howitzer battery was now landed, and at 1.30 began to bombard the Mahdi's Tomb. This part of the proceedings was plainly visible to us, waiting and watching on the ridge, and its interest even distracted attention from the Dervish army. The dome of the tomb rose tall and prominent above the mud houses of the city. A lyddite shell burst over it—a great flash, a white ball of smoke, and, after a pause, the dull thud of the distant explosion. Another followed. At the third shot, instead of the white smoke, there was a prodigious cloud of red dust, in which the whole tomb disappeared. When this cleared away we saw that, instead of being pointed, it was now flat-topped. Other shells continued to strike it with like effect, some breaking holes in the dome, others smashing off the cupolas, all enveloping it in dust.
All this time the Dervishes were coming nearer, and the steady and continuous advance of the great army compelled the Egyptian cavalry to mount their horses and trot off to some safer point of view. Colonel Broadwood conceived his direct line of retreat to camp threatened, and shortly after one o'clock he began a regular retirement. Eight squadrons of Egyptian cavalry and the Horse Artillery moved off first. Five companies of the Camel Corps, a Maxim gun section, and the ninth squadron of cavalry followed as a rear-guard under Major Tudway. The Dervish horsemen contented themselves with firing occasional shots, which were replied to by the Camel Corps with volleys whenever the ground was suited to dismounted action. From time to time one of the more daring Arabs would gallop after the retreating squadrons, but a shot from a carbine or a threatened advance always brought the adventurous horseman to a halt. The retirement was continued without serious interference, and the boggy ground of the Khor Shambat was recrossed in safety.
As soon as the Egyptian squadrons—a darker mass under the dark hills to the westward—were seen to be in retirement, the 21st Lancers were withdrawn slowly along the sandy ridge towards the rocks of Surgham—the position whence we had first seen the Dervish army. The regiment wheeled about and fell back by alternate wings, dropping two detached troops to the rear and flanks to make the enemy's patrols keep their distance. But when the Arab horsemen saw all the cavalry retiring they became very bold, and numerous small groups of fives and sixes began to draw nearer at a trot. Accordingly, whenever the ground was favourable, the squadrons halted in turn for a few minutes to fire on them. In this way perhaps half-a-dozen were killed or wounded. The others, however, paid little attention to the bullets, and continued to pry curiously, until at last it was thought necessary to send a troop to drive them away. The score of Lancers galloped back towards the inquisitive patrols in the most earnest fashion. The Dervishes, although more numerous, were scattered about in small parties, and, being unable to collect, they declined the combat. The great army, however, still advanced majestically, pressing the cavalry back before it; and it was evident that if the Khalifa's movement continued, in spite of it being nearly one o'clock, there would be a collision between the main forces before the night.
From the summit of the black hill of Surgham the scene was extraordinary. The great army of Dervishes was dwarfed by the size of the landscape to mere dark smears and smudges on the brown of the plain. Looking east, another army was now visible—the British and Egyptian army. All six brigades had passed the Kerreri Hills, and now stood drawn up in a crescent, with their backs to the Nile. The transport and the houses of the village of Egeiga filled the enclosed space. Neither force could see the other, though but five miles divided them. The array of the enemy was, without doubt, both longer and deeper. Yet there seemed a superior strength in the solid battalions, whose lines were so straight that they might have been drawn with a ruler.