Yet, even as the columns filled him with dread, he marvelled at the calm of the men with whom he rode. The calmness, Lord John observed, came from the Duke, to whom men were irresistibly attracted as though his confidence would somehow communicate by proximity. The Duke watched the approaching columns with a keen eye, but still had time to laugh at some jest made by Alava, the Spanish commissioner. The only time Rossendale saw the Duke frown was when a brief shower of rain, gone almost as soon as it arrived, made him shake out his cloak and drape it round his shoulders. “I cannot bear a drenching, nor will I abide umbrellas,” he spoke to Alava in French.

“You could have a canopy held by four stout men?” Alava, an old and valued friend from the Duke’s Spanish battles, suggested. “Like some Mohammetan potentate?”

The Duke gave his odd horse-neigh of a laugh. “That would serve very well! I like that notion! A Mohammetan canopy, eh?”

“And a harem, why not?”

“Why not, indeed?” The Duke gently drummed his fingers on the small writing desk that was built onto the pommel of his saddle. To Lord John the gesture did not seem to be a nervous reaction, but rather to express the Duke’s impatience at the lumbering French columns. By now the enemy skirmishers were close enough to annoy the Duke’s party. Their bullets whiplashed and hummed about the horsemen. Two of the Duke’s aides were hit; one fatally just two paces to the Duke’s left. The Duke gave the dead man a glance, then frowned towards the French galloper guns. “They’ll never do a damn thing with those light cannon,” he complained, as though his enemy’s inefficiency offended him, then, switching into French, he asked Alava whether he did not agree that the French were deploying more skirmishers than usual.

“Definitely more,” Alava confirmed, but with no more excitement in his voice than if he was sharing a day’s rough shooting with the Duke.

The Dutch-Belgians ran, which caused a compression of the Duke’s lips, but then, knowing what could and could not be mended, he simply ordered a British battalion into the gap. He rode further to his left, cantering his horse behind the waiting redcoats. The Earl of Uxbridge and his staff followed. The Duke frowned again as the French columns began to unfold into line, but the unexpected manoeuvre did not seem to rattle him. “Now’s your time!” the Duke called to the nearest redcoat battalion.

The redcoats stood and the volleys began. Lord John, trailing with his master behind the Duke, saw how the French attempt to form line was never completed because of the destructive British fire. The French flanks would not wheel up the slope into the face of the musket volleys, so instead the whole enemy mass edged uphill in neither line nor column, but in a half-way formation instead. To Lord John’s untutored eye, and despite the momentary French confusion, it still looked like a frighteningly unequal battle; a mass of Frenchmen poised just beneath the thin and fragile line of redcoats. The mass was also still advancing. Its leading ranks were being bled and beaten by the flail of the British volleys, but still the French pressed uphill, stepping over their dead, and shouting their war cry. Worse, the Cuirassiers who had just destroyed the Red Germans now rode west of the high road to escape the cannon-fire and threatened to attack the thin British line.,

The Duke had seen it all, and understood it all. He turned to Uxbridge. “Your Heavies are ready, Uxbridge?”

“Indeed they are, Your Grace!”

It took Lord John a moment to understand the elegance of the Duke’s solution. The French were poised on the brink of a shattering success. Their columns were inching uphill, and in a moment they would be reinforced by the heavy cavalry that would fall on the redcoat flank like a torrent of steel. The Duke’s line would be shattered, the French infantry would pour through, then more cavalry would stream across the valley to finish the rout.

Except that the Duke’s counter-stroke was ready. Horse would oppose horse and the British heavy cavalry would be unleashed on the Emperor’s gros freres. The King’s Own Household troops: the Life Guards and King’s Dragoon Guards and Blues, together with the Union Brigade of the Royals, the Scots Greys and the Inniskilling Horse would save the army.

Lord John turned his own horse, drew his borrowed sword, and raced after the Earl of Uxbridge. “Harry.” You must let me come!“ This was the chance Lord John had prayed and waited for. He saw other staff officers, Christopher Manvell among them, hurrying to join their regiments. ”For God’s sake, Harry, let me fight!“ Lord John pleaded again.

“You can fight, Johnny! The more the merrier! We’ll take their horse, then break their infantry!”

The cream of the British cavalry would go to shatter the French attack. Lord John, his borrowed sword bright in his hand, rode to find his honour again. In battle.

Almost two and a half thousand horsemen assembled just behind the ridge’s flat crest. Men pulled on gleaming helmets that were topped with long horsehair plumes. The Scots on their huge white horses wore Grenadier bearskins as memorials of the day they had captured the colour of Louis XIV’s household guards at Ramillies. They tightened their chin straps and made the usual small jokes of men facing battle. The air was rich with the smell of horse dung.

An officer raised a gloved hand, held it motionless for a second, then dropped it to point at where the gun smoke hung above the valley. A bugle sounded the advance as the long attack lines moved forward in a jingle of curb chains and creak of leather.

They were the heavy cavalry of Britain; the Sovereign’s Guard and the Union Brigade. They were the best-mounted cavalry in all the world, and the worst led.

They rode big strong horses reared on rich English and Irish grassland. The horses were fresh, unblooded and eager. The riders drew their swords and looped the weapons’ leather straps round their gauntletted wrists. Each sword blade was thirty-five inches of heavy steel that had been sharpened to a spear point. The bugle called the trot and the long plumes began to undulate behind the ranks. Some men took a last pull of rum from their canteens while others touched their lucky charms. A horse curled its lips to show long yellow teeth, another whinnied with excitement. A man spat a wad of tobacco, then wrapped his horse’s reins round his left wrist. The leading ranks of cavalry were at the crest and they could see, through the scrims of cannon smoke, that the valley was a killer’s playground; a wide field crammed with an unsuspecting enemy. Twenty thousand French infantry had crossed the valley and two and a half thousand cavalry would now charge at their exposed flank. The horsemen spurred into a canter, their plumes tossing wild in the smoky wind. Sabretaches and empty scabbards flapped at their sides. A guidon embroidered in gold thread led them down the slope. The troopers’ ranks were already ragged for each man only wanted to close on the enemy, while their officers, not wanting to be outrun, raced ahead as though they rode on a hunting field and feared to miss the kill.

Then, at last, the trumpeters sounded the full charge. The ten notes, rising in triplets, pierced to the final high and brilliant tone which threw the horsemen on. Damn caution. Damn the slow approach and the final steady charge that would bring the horses home as one cohesive mass. This was war! This was the hunting field with a human quarry, and glory did not wait for the last man to form line, and so the trumpet shivered the blood with its madman’s call. Charge home, and the devil bugger the hindmost.

They made a glorious charge of bright horse that slanted across the face of the ridge’s forward slope like a flood. Ahead of them were the Cuirassiers, and beyond the breast-plated enemy horsemen were the infantry who were neither in column nor in line. None of the French was expecting the attack.