Abdullah's followers, calling themselves the "Ansar" and known to the British as the Dervishes, numbered around 50,000, including some 3,000 cavalry. They were split into five groups—a force of 8,000 under Osman Azrak was arrayed directly opposite the British, in a shallow arc along a mile (1.6 km) of a low ridge leading onto the plain, and the other Mahdist forces were initially concealed from Kitchener's force. Abdullah al-Taashi and 17,000 men were concealed behind the Surgham Hills to the west and rear of Osman Azrak's force, with 20,000 more positioned to the north-west, close to the front behind the Kerreri hills, commanded by Ali wad Hilu and Osman Sheikh ed-Din. A final force of around 8,000 was gathered on the slope on the right flank of Azrak's force.