The River War: An Historical Account of the Reconquest of the Sudan is an 1899 book written by Winston Churchill while he was still an officer in the British army. The book provides a history of the British involvement in the Sudan and the conflict between the British forces led by Lord Kitchener and Dervish forces led by Khalifa Abdallahi ibn Muhammad, heir to the self-proclaimed Mahdi Muhammad Ahmad who had embarked on a campaign to conquer Egypt, to drive out the non-Muslim infidels and make way for the second coming of the Islamic Mahdi. The River War was Churchill's second published book after The Story of the Malakand Field Force , and originally filled two volumes with over 1000 pages in 1899. The River War was subsequently abridged to one volume in 1902.