The preparations for this fresh advance against the Mahdi were made with care, and on an extensive scale. Several regiments were sent from Egypt, and in the spring of the year a permanent camp was established for their accommodation at Omdurman, on the western bank of the Nile, opposite Khartoum. Here, by the end of June 1883, was assembled a force officially computed to number 7000 infantry, 120 cuirassiers, 300 irregular cavalry, and not fewer than 30 pieces of artillery, including rockets and mortars. Colonel Hicks was given the nominal command, several English and other European officers were appointed to serve under him, and the Khedive specially ordered the Governor-General to accompany the expedition that was to put an end to the Mahdi's triumph. Such was the interest, and, it may be added, confidence, felt in the expedition, that two special correspondents, one of whom was Edmond O'Donovan, who had made himself famous a few years earlier by reaching the Turcoman stronghold of Merv, were ordered to accompany it, and report its achievements. The Mahdi learnt in good time of the extensive preparations being made for this expedition, but he was not dismayed, because all the fighting tribes of Kordofan, Bahr Gazelle, and Darfour were now at his back, and he knew that he could count on the devotion of 100,000 fanatical warriors. Still, he and his henchman Abdullah, who supplied the military brains to the cause, were not disposed to throw away a chance, and the threatening appearance of the Egyptian military preparations led them to conceive the really brilliant idea of stirring up trouble in the rear of Khartoum. For this purpose a man of extraordinary energy and influence was ready to their hand in Osman Digma, a slave-dealer of Souakim, who might truly be called the Zebehr of the Eastern Soudan. This man hastened to Souakim as the delegate of the Mahdi, from whom he brought special proclamations, calling on the tribes to rise for a Holy War. Although this move subsequently aggravated the Egyptian position and extended the military triumphs of the Mahdi, it did not attain the immediate object for which it was conceived, as the Hicks Expedition set out on its ill-omened march before Osman had struck a blow.