Horatio Herbert Kitchener, 1st Earl Kitchener, (; 24 June 1850 5 June 1916) was an Anglo-Irish senior British Army officer and colonial administrator. Kitchener came to prominence for his imperial campaigns, his scorched earth policy against the Boers, his expansion of Lord Roberts' concentration camps during the Second Boer War and his central role in the early part of the First World War.

Kitchener was credited in 1898 for having won the Battle of Omdurman and securing control of the Sudan for which he was made Baron Kitchener of Khartoum. As Chief of Staff (19001902) in the Second Boer War he played a key role in Lord Roberts' conquest of the Boer Republics, then succeeded Roberts as commander-in-chief by which time Boer forces had taken to guerrilla fighting and British forces imprisoned Boer civilians in concentration camps. His term as Commander-in-Chief (19021909) of the Army in India saw him quarrel with another eminent proconsul, the Viceroy Lord Curzon, who eventually resigned. Kitchener then returned to Egypt as British Agent and Consul-General (de facto administrator).

In 1914, at the start of the First World War, Kitchener became Secretary of State for War, a Cabinet Minister. One of the few to foresee a long war, lasting for at least three years, and also having the authority to act effectively on that perception, he organised the largest volunteer army that Britain had seen, and oversaw a significant expansion of materiel production to fight on the Western Front. Despite having warned of the difficulty of provisioning for a long war, he was blamed for the shortage of shells in the spring of 1915 one of the events leading to the formation of a coalition government and stripped of his control over munitions and strategy.

On 5 June 1916, Kitchener was making his way to Russia on HMS Hampshire to attend negotiations with Tsar Nicholas II when in bad weather the ship struck a German mine 1.5 miles (2.4 km) west of Orkney, Scotland, and sank. Kitchener was among 737 who died.

The Mahdist War (Arabic: الثورة المهدية ath-Thawra al-Mahdiyya; 1881–1899) was a war between the Mahdist Sudanese of the religious leader Muhammad Ahmad bin Abd Allah, who had proclaimed himself the "Mahdi" of Islam (the "Guided One"), and the forces of the Khedivate of Egypt, initially, and later the forces of Britain. Eighteen years of war resulted in the nominally joint-rule state of the Anglo-Egyptian Sudan (1899–1956), a de jure condominium of the British Empire and the Kingdom of Egypt in which Britain had de facto control over the Sudan. The Sudanese launched several unsuccessful invasions of their neighbours, expanding the scale of the conflict to include not only Britain and Egypt but the Italian Empire, the Congo Free State and the Ethiopian Empire.

The British participation in the war is called the Sudan campaign. Other names for this war include the Mahdist Revolt, the Anglo–Sudan War and the Sudanese Mahdist Revolt.