The order was relayed from battalion to battalion and each of the lines of infantry steadily manoeuvred into blocks, three ranks deep. The front rank knelt, each man resting the butt of his musket against a boot so that the bayonets angled out to present a bristling line of steel points on each face of the formation. Soon the reverse slope was covered in a patchwork of red rectangles, loosely staggered like elongated squares of a chessboard. Arthur and his staff took their place in the middle of a battalion close to the ridge, and waited. Above them the British artillery fired away at the advancing cavalry as long as they dared, then abandoned their guns and rushed for the shelter of the nearest square, throwing themselves flat beneath the outstretched bayonets. A handful of crews had the presence of mind to remove a wheel from their guns and run it down the slope with them, leaving their gun immobilised.

‘Here they come,’ Somerset muttered as the ground shook beneath the impact of four thousand cavalry ascending the forward slope. The sharp notes of bugles sounded an increase in pace and then the first of the enemy appeared on the ridge, wearing the crested helmets of dragoons. They came on, sweeping past the abandoned guns, their front extending for a thousand yards, charging towards the squares in a deadly wave of gleaming swords and deadly lance points.

‘Hold your ground!’ the colonel of the battalion bellowed to his men. ‘For England!’

Arthur watched a squadron of cuirassiers swing towards the square, their gleaming breastplates shimmering as their mounts stretched their necks and galloped down the gentle slope.

‘Fire!’ the colonel shouted and the view of the enemy was obliterated by smoke. Arthur heard the thud of the bullets impacting on horseflesh, and the clatter as they struck the cuirassiers’ breastplates. The smoke eddied away revealing horses and men strewn across the flattened crops.

‘Fire at will!’ the colonel ordered.

On all sides now the first volleys blazed out and enemy cavalry tumbled to the ground. Then they were in amongst the squares, flowing between the rows of bayonets, like a wave crashing against rocks and forced to channel its flow between immovable obstacles. The most fearless of the cavalry steered their mounts up to the lines of bayonets and then attempted to lean out and slash their blades down at one of the kneeling men. But, almost to a man, they were shot out of their saddles before they could strike.