In 1892 Herbert Kitchener (later Lord Kitchener) became sirdar, or commander, of the Egyptian army and started preparations for the reconquest of Sudan. The British decision to occupy Sudan resulted in part from international developments that required the country be brought under British supervision. By the early 1890s, British, French, and Belgian claims had converged at the Nile headwaters. Britain feared that the other colonial powers would take advantage of Sudan's instability to acquire territory previously annexed to Egypt. Apart from these political considerations, Britain wanted to establish control over the Nile to safeguard a planned irrigation dam at Aswan.
In 1895 the British government authorized Kitchener to launch a campaign to reconquer Sudan. Britain provided men and matériel while Egypt financed the expedition. The Anglo-Egyptian Nile Expeditionary Force included 25,800 men, 8,600 of whom were British. The remainder were troops belonging to Egyptian units that included six battalions recruited in southern Sudan. An armed river flotilla escorted the force, which also had artillery support. In preparation for the attack, the British established army headquarters at Wadi Halfa and extended and reinforced the perimeter defenses around Sawakin. In March 1896, the campaign started; in September, Kitchener captured Dunqulah. The British then constructed a rail line from Wadi Halfa to Abu Hamad and an extension parallel to the Nile to transport troops and supplies to Barbar. Anglo-Egyptian units fought a sharp action at Abu Hamad, but there was little other significant resistance until Kitchener reached Atbarah and defeated the Ansar. After this engagement, Kitchener's soldiers marched and sailed toward Omdurman, where the Khalifa made his last stand.
On September 2, 1898, the Khalifa committed his 52,000-man army to a frontal assault against the Anglo-Egyptian force, which was massed on the plain outside Omdurman. The outcome never was in doubt, largely because of superior British firepower. During the five-hour battle, about 11,000 Mahdists died whereas AngloEgyptian losses amounted to 48 dead and fewer than 400 wounded.
Mopping-up operations required several years, but organized resistance ended when the Khalifa, who had escaped to Kurdufan, died in fighting at Umm Diwaykarat in November 1899. Many areas welcomed the downfall of his regime. Sudan's economy had been all but destroyed during his reign and the population had declined by approximately one-half because of famine, disease, persecution, and warfare. Moreover, none of the country's traditional institutions or loyalties remained intact. Tribes had been divided in their attitudes toward Mahdism, religious brotherhoods had been weakened, and orthodox religious leaders had vanished.
Britain decided to reconquer the Sudan, which was controlled by the Mahdists under the khalifa Abdullah (1846?-99) and which was of increasing colonial interest to the Italians and French in Africa. An Anglo-Egyptian army led by General Horatio Herbert Kitchener (1850-1916) advanced south from Egypt up the Nile River into the Sudan. Accompanied by a river gunboat flotilla, Kitchener constructed a railway as he moved and encountered stiff resistance from the Mahdists. The Anglo-Egyptian force captured Dongola (September 21, 1896) and Abu Hamed (August 7, 1897) and was victorious against the Mahdists at the Battle of the Atbara River (April 8, 1898). A 40,000-man army of dervishes and Mahdists, under the command of the khalifa, savagely attacked Kitchener's army of about 26,000 men at Omdurman on the Nile, just north of Khartoum, on September 2, 1898. The attack was repelled with machine guns, and the khalifa suffered heavy casualties. Kitchener counterattacked, and his cavalry - the 21st Lancers, among who was Winston Churchill (1874-1965) - bravely drove the dervishes from the field. The khalifa and his remaining forces took flight and were pursued into Kordofan, where they managed to hold their ground for more than a year. On November 24, 1899, the Mahdist forces were completely destroyed, and the khalifa was slain in battle. The condominium government of the Anglo-Egyptian Sudan was then established.
For more information on this subject see Winston S. Churchill, The River War: An Historical Account of the Reconquest of the Soudan (1899).