Kitchener was credited in 1898 for winning the Battle of Omdurman and securing control of the Sudan for which he was made Baron Kitchener of Khartoum. As Chief of Staff (1900–1902) 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 (1902–09) 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).