From that day to this I do not think the Khalifa has ever had such an ovation. At that time Omdurman was unusually full, trade was brisk, and it was thought that he would now undertake the invasion of Egypt. But, as it soon transpired, he had still a good deal of work to do in the Sudan itself. One enemy he undoubtedly had--this was El Merhdi Abu Rof, a descendant of the ancient Kings of Sennar and sheikh of the great Gehena tribe, which, amongst the mass of Arabs allied to the Mahdi, had persistently held aloof. This tribe possessed a large number of camels of a curious dark-coloured breed, and also quantities of gray-coloured cows. El Merhdi had instigated a purely local movement of his own against the Government, and had once besieged and set fire to Sennar; long before Abu Anga's arrival he had shown hostility to the Khalifa, and had annihilated a number of small Dervish garrisons; his power extended as far as Karkoj, and he levied taxes on all boats going north. For a long time the Khalifa had let him alone, but now finding himself in possession of such an enormous force, he decided to attack El Merhdi, more especially as at this time his audacity considerably endangered the navigation of the Blue Nile, from whence Omdurman drew its main supplies of corn. He therefore despatched Ismail Wad el Andok up the Blue Nile, while Abdullah Wad Ibrahim was sent up the White Nile. El Merhdi, attacked thus on both sides, was powerless; he was unable to withstand the advance of the victorious black troops, and he and almost all his Arabs were killed. El Merhdi's head was sent to Omdurman, where it was exposed for a long time on the gallows, and was at last thrown into the pit in which lay the heads of Bishir and those who had been slain with him.