Had he marched along the banks of the Nile, he would have been exposed to the fire of the gunboats, but these could not have arrested his course.

The country round Berber was favourable to the action of his cavalry, and if defeated he could have fallen back, unmolested, through Metemmeh on Omdurman; but by crossing the river he practically cut himself off from the Dervish base, and now had only a desert behind him; for we had taken over Kassala from the Italians, and the Egyptian battalion there, and a large force of friendly Arabs, would prevent him from retiring up the banks of the Atbara.
Mahmud's plan was to march along the Nile to Ahab, then to cross the desert to Hudi, at an angle of the river; whence a direct march, of twenty-five miles, would take him to Berber, and in this way he would avoid our strong position at the junction of the Atbara and the Nile.
It would have been easy for the gunboats to prevent Mahmud from crossing the Nile, but the Sirdar was glad to allow him to do so.

The movement afforded him time to concentrate his force, and to get up large supplies.

For, each day, the distance that these could be transported by the railway had increased; and he saw that, when the time for fighting came, the victory would be a decisive one; and that few, indeed, of Mahmud's men would ever be able to make their way to Omdurman, and swell the Khalifa's force there.
On one occasion, however, the gunboats went up to watch what was going on, and take advantage of any opportunity that might offer to destroy some of Mahmud's boats, and thus render the work of his getting his force over slower and more difficult.

An entrenchment had been thrown up at the point where the Dervishes crossed, and this had been manned by two hundred and fifty riflemen.