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.