And all this time his terrible antagonist watched him as a tiger gloats on a helpless and certain prey—­silent, merciless, inexorable.  Then the end came suddenly.  As soon as the process of attrition was sufficiently far advanced to demoralise the Dervish host, without completely dissolving them, the Sirdar and his army moved.  The victim, as if petrified, was powerless to fly.  The tiger crept forward two measured strides—­ from Ras-el-Hudi to Abadar, from Abadar to Umdabia—­crouched for a moment, and then bounded with irresistible fury upon its prey and tore it to pieces.

Such is a brief strategic account of the Atbara campaign; but the tale must be told in full.

On the 23rd of January the Khalifa, having learned of the arrival of British troops near Abu Hamed, and baffled by the disputes about the command of his army, ordered Kerreri camp to be broken up, and permitted his forces to return within the city, which he continued to fortify.  A few days later he authorised Mahmud to advance against Berber.  What he had not dared with 60,000 men he now attempted with 20,000.  The course of action which had for three months offered a good hope of success he resolved to pursue only when it led to ruin.  He forbade the advance while it was advisable.  When it was already become mad and fatal he commanded it.  And this was a man whose reputation for intelligence and military skill had been bloodily demonstrated!

The gunboats ceaselessly patrolled the river, and exchanged shots with the Dervish forts.  Throughout January nothing of note had happened.  The reports of spies showed the Khalifa to be at Kerreri or in Omdurman.  Ahmed Fedil held the Shabluka Gorge, Osman Digna was at Shendi, and his presence was proved by the construction of two new forts on that side of the river.  But beyond this the Dervishes had remained passive.  On the 12th of February, however, it was noticed that their small outpost at Khulli had been withdrawn.  This event seemed to point to a renewal of activity.  It was felt that some important movement impended.  But it was not until the 15th that its nature was apparent, and the gunboats were able to report definitely that Mahmud was crossing to the east bank of the Nile.  The flotilla exerted itself to harass the Dervishes and impede the transportation; but although several sailing-boats and other river craft were captured, Mahmud succeeded in moving his whole army to Shendi by the 28th of February.  His own headquarters were established at Hosh-ben-Naga, a little village about five miles further south.  A delay of more than a fortnight followed, during which the gunboats exercised the utmost vigilance.  The Suakin-Berber road was again closed for caravans, and the Sirdar himself proceeded to Berber.  On the 11th of March the remnants of the Jaalin tribe, having collected at Gakdul, re-occupied the now abandoned Metemma, to find its streets and houses choked with the decaying bodies of their relations.  On the 13th the Egyptian look-out station, which had been established on Shebaliya island, was attacked by the Dervishes, and in the skirmish that ensued Major Sitwell was wounded.  On the same day the enemy were reported moving northwards to Aliab, and it became evident that Mahmud had begun his advance.