The column shuffled forward again, and rippled warily round the body as the men stared at their dead comrade in fear and anger. He was only the first that they encountered that night. By the time the sky began to lighten, with promise of yet another day of unbearable heat, they had passed several more corpses. Some had been beheaded and all of them showed signs of torture and mutilation. The way ahead was strewn with abandoned equipment and Napoleon and his men began to nurse dreadful fears about the fate of the men who had marched before them.

Again, the searing heat and dazzling glare pinned them to the wasteland as they followed the tracks of Desaix and his divisions. Late in the morning there was a shout from the company of guides, as Napoleon’s bodyguard had come to be called, who were screening their advance. Napoleon rose up in his saddle to squint in the direction indicated. A mile away, on the crest of a dune, a small party of dark-robed figures mounted on camels was shadowing the column.

‘Looks like some of those Bedouin you mentioned.’

Berthier nodded as he stared at the distant riders. ‘I’ll pass the word back down the column. I don’t imagine there’ll be many stragglers today, sir.’

‘No . . .’

Despite Napoleon’s orders the men could not resist the thirst that tormented them and nearly every canteen was empty long before they stopped under the midday sun and rested until it had inched down towards the western horizon. Then they rose up and continued again, their shadows stretching before them thin and gaunt and obscured by the dusty haze kicked up by their heavy boots. The men were exhausted and marched at a monotonous pace, dazed expressions on their faces. Here and there a man passed a dry, tacky tongue over cracked lips and winced at the pain it produced. Napoleon and the other officers had spare canteens hanging from their saddles and drank from them as discreetly as possible. Even so, the eyes of the nearest men flickered towards them with an intensity born of desperation as their parched throats burned in agony.

They rested again shortly after midnight and sat huddled together against the cold night air. Away to the west a sand dune was dimly highlighted by the glow of a campfire and a dark silhouette kept watch over the intervening desert. Napoleon stared at the Bedouin for a long time, wondering at the hardiness of a people who could endure such a hostile environment.What kind of man would choose such a life? But if this wasteland was the kind of terrain over which the Egyptian campaign would be fought, then he would do well to recruit these desert warriors to his side.