At the Battle of Omdurman, an army commanded by the British General Sir Herbert Kitchener defeated the army of Abdullah al-Taashi, the successor to the self-proclaimed Mahdi, Muhammad Ahmad. Kitchener was seeking revenge for the 1885 death of General Gordon. It was a demonstration of the superiority of a highly disciplined army equipped with modern rifles, machine guns, and artillery over a force twice their size armed with older weapons, and marked the success of British efforts to re-conquer the Sudan. However, it was not until the 1899 Battle of Umm Diwaykarat that the final Mahdist forces were defeated.