It had not been proposed to employ Lord Wolseley in the expedition, but on August 26, he was appointed to command the troops upon the Nile. He reached Cairo on September 9, when there were actually in Egypt, or on their way thither, a regiment of cavalry, one battery of Royal Horse artillery, one of Royal Field artillery, one camel battery of mountain guns, and two garrison batteries; four companies of Royal Engineers, one of which was at Suakim; a battalion of mounted infantry, 423 strong; and thirteen and a half battalions of infantry--in all, nearly 11,000 officers and men, among whom were the first battalion of the Royal Irish regiment. Not all these troops, however, were available for the actual operations at Khartoum when that far-distant goal should be approached. The garrisons of Cairo and Alexandria absorbed four and a half battalions of infantry, a squadron of cavalry, and all the artillery except the mountain guns. Though the Egyptian army held the line of communication from Cairo to Hannek, it was considered necessary to strengthen this section with a British battalion, while to secure the Nile between Hannek and Berber, at least five battalions would be required. Lord Wolseley aimed at placing about 5400 men in line at Shendi, a place on the river about 100 miles south of Berber, and the same distance to the northward of Khartoum, and after making allowance for the inevitable wastage of troops in an expedition such as he was to conduct, and for the possibility that he might have to send part of his column on a sudden dash across the desert, he asked the War Office to supply him with eleven hundred more men, volunteers from regular regiments at home, to be turned into “camelry”--_i.e._, infantry mounted upon camels. The request was granted, and these reinforcements arrived in time to reap a large share of the honours of the campaign.
Before any troops could be moved to Shendi, through a country from which little or no food could be obtained, it was necessary to form an advanced base as high up the river as possible, where stores of all kinds were to be collected before the main body began to arrive from Cairo. It was also necessary to establish along the line of communication on the river a chain of intermediate depôts, from which the troops would draw rations and thus preserve intact the cargo of stores with which each whale-boat was to be freighted. Korti was selected for the advanced base, and there, when the first thousand miles of its journey from the sea was accomplished, the expeditionary force was to effect its preliminary concentration.[255] As far as Wadi Halfa, about 750 miles above Cairo, the navigation of the Nile presents no great difficulties, and every available river steamer and river boat was pressed into the service. But above Wadi Halfa a formidable series of cataracts, or rapids as they should more accurately be termed, proved fatal to so many of the native craft that the transport of stores to the higher reaches had almost entirely to be carried out by the whale-boats. It was not until the 1st of November that a sufficient quantity of supplies had been sent up the river to warrant Lord Wolseley in moving the main body of his infantry. Then as speedily as possible each corps was despatched in turn on its journey southward. Towards the end of December the first battalion of infantry reached Korti, where the camelry, who had marched along the banks of the Nile, were beginning to assemble; in about four weeks more the last regiments arrived, and by the end of January the preliminary concentration had been successfully accomplished.