It was dawn on the northern frontier of France; a border marked only by a shallow stream which ran between the stunted trunks of pollarded willows. A paved high road forded the stream. The road led north from France into the Dutch province of Belgium, but there was neither guardpost nor gate to show where the road left the French Empire to enter the Kingdom of the Netherlands. There was just the summer-shrunken stream from which a pale mist drifted to lie in shadowy skeins across the plump fields of wheat and rye and barley.

The rising sun appeared like a swollen red ball suspended low in the tenuous mist. The sky was still dark in the west. An owl flew over the ford, banked into a beechwood and gave a last hollow call, which was lost in the dawn’s loud chorus that seemed to presage a bright hot summer’s day in this rich and placid countryside. The cloudless sky promised a day for haymaking, or a day for lovers to stroll through heavy-leafed woods to rest beside the green cool of a streambank. It was a perfect midsummer’s dawn on the northern border of France and for a moment, for a last heart-aching moment, the world was at peace.

Then hundreds of hooves crashed through the ford, spattering water bright into the mist. Uniformed men, long swords in their hands, rode north-out of France. The men were Dragoons who wore brass helmets covered with drab cloth so the rising sun would not reflect from the shining metal to betray their position. The horsemen had short-barrelled muskets thrust into bucket holsters on their saddles.

The Dragoons were the vanguard of an army. A hundred and twenty-five thousand men were marching north on every road that led to the river-crossing at Charleroi. This was invasion; an army flooding across an unguarded frontier with wagons and coaches and ambulances and three hundred and forty-four guns and thirty thousand horses and portable forges and pontoon bridges and whores and wives and colours and lances and muskets and sabres and all the hopes of France. This was the Emperor Napoleon’s Army of the North and it marched towards the waiting Dutch, British and Prussian forces.

The French Dragoons crossed the frontier with drawn swords, but the weapons served no purpose other than to dignify the moment with a suitable melodrama, for there was not so much as a single Dutch customs officer to oppose the invasion. There were just the mist and the empty roads, and the far-off crowing of cockerels in the dawn. A few dogs barked as the invading cavalrymen captured the first Dutch villages unopposed. The Dragoons hammered their sword hilts against doors and window shutters, demanding to know whether any British or Prussian soldiers were billeted within.

“They’re all to the north. They hardly ever show themselves here!” The villagers spoke French; indeed, they thought of themselves as French citizens and consequently welcomed the helmeted Dragoons with cups of wine and offers of food. To these reluctant Dutchmen the invasion was a liberation, and even the weather matched their joy; the sun was climbing into a cloudless sky and beginning to burn off the mist which still clung in the leafy valleys.

On the main highway leading to Charleroi and Brussels the Dragoons were clattering along at a fine pace, almost as if this was an exercise in Provence instead of war. A lieutenant of Dragoons was so dismissive of any danger that he was eagerly telling his Sergeant how the new science of phrenology measured human aptitudes from the shape of a man’s skull. The Lieutenant opined that when the science was properly understood all promotion in the army would be based on careful skull measurements. “We’ll be able to measure courage and decisiveness, common sense and honesty, and all with a pair of calipers and a measuring tape!”

The Sergeant did not respond. He and his officer rode at the head of their squadron, and were thus at the very tip of the advancing French army. In truth the Sergeant was not really listening to the Lieutenant’s enthusiastic explanation; instead he was partly anticipating the Belgian girls and partly worrying when this headlong advance would run into the enemy picquets. Surely the British and Prussians had not fled?

The Lieutenant was somewhat piqued by his Sergeant’s apparent lack of interest in phrenology, though the Sergeant’s low and scowling brow ridge undoubtedly betrayed the scientific reason for his inability to accept new ideas. The Lieutenant nevertheless persisted in trying to enlighten the veteran soldier. “They’ve done studies on the criminal classes in Paris, Sergeant, and have discovered a remarkable correlation between — „

The remarkable correlation remained a mystery, because the hedgerow thirty yards ahead of the two horsemen exploded with musket-fire and the Lieutenant’s horse collapsed, shot in the chest. The horse screamed. Blood frothed at its teeth as it lashed frantically with its hooves. The Lieutenant, thrown from the saddle, was kicked in the pelvis by a thrashing hoof. He screamed as loudly as his horse that was now blocking the high road with its flailing death throes. The astonished Dragoons could hear the enemy ramrods rattling in their musket barrels. The Sergeant looked back at the troopers. “One of you kill that bloody horse!”

More shots hammered from the hedge. The ambushers were good. They had allowed the French horsemen to come very close before they opened fire. The Dragoons sheathed their long swords and drew their carbines, but their aim from horseback was uncertain and the short-barrelled carbine was a weapon of notorious inaccuracy. The Lieutenant’s horse still lashed and kicked on the road. The Sergeant was shouting for his men to advance. A trumpet called behind, ordering another troop to file right into a field of growing wheat. A trooper shot the Lieutenant’s horse, leaning from his saddle to put the bullet plumb into the beast’s skull. Another horse fell, this one with a leg bone shattered by a musket-ball. A Dragoon was lying in the ditch, his helmet fallen into a nettle patch. Horses crashed past the wounded Lieutenant, their hooves spurting mud and road-flints into the air. The Sergeant’s long sword shone silver.

More shots, but this time the gouts of white smoke were scattered more thinly along the hedgerow. “They’re retreating, sir!” the Sergeant shouted to an officer far behind him, then, not waiting for any orders, spurred his horse forward. “Charge!”

The French Dragoons swept past the line of the hedge. They could see no enemy in the long-shadowed landscape, but they knew the ambushers had to be close. The Sergeant, suspecting that the enemy infantry was hiding in the mist-skeined wheat field, turned his horse off the lane, forced it through a ditch and so up into the wheat. He saw movement at the far side of the field, close by a dark-leafed wood. The movement resolved into men running towards the trees. The men wore dark blue uniform coats and had black shakos with silver rims. Prussian infantry. “There they are!” The Sergeant pointed at the enemy with his sword. “After the bastards!”

Thirty Dragoons followed the Sergeant. They thrust their carbines into the bucket holsters on their saddles and dragged out their long straight-bladed swords. Prussian muskets pricked flame from the wood’s edge, but the shooting was at too long a range and only one French horse tumbled into the wheat. The remaining Dragoons swept on. The enemy picquet that had ambushed the French vanguard was hurrying to the shelter of the wood, but some of them had left their retreat too late and the Dragoons caught them. The Sergeant galloped past a man and cut back with a savage slash of his sword.