As the word spread swiftly through the ranks of the men who had held the ridge all day the army swept forward, infantry mixed with cavalry as they chased after the French. Arthur rode with them and at his approach his men cheered him for all they were worth. The French spilled out across the landscape as they desperately tried to escape, abandoning their guns, caissons and wagons along with their wounded. Arthur searched for sign of Bonaparte, but the Emperor’s distinctive white horse was nowhere to be seen. He reined in briefly at La Belle Alliance, where men from one of the Dutch cavalry regiments were busy ransacking what was left of the French headquarters in the gathering dusk. A hundred yards further down the road he came upon the first of the Prussian soldiers. They were busy bayoneting wounded Frenchmen and glanced up at him suspiciously until they realised from his beaming smile that he could hardly be an enemy. A short distance further on he saw a cluster of Prussian officers on horseback. At their head was a stiff-backed, elderly man with a fabulous growth of silvery hair on his cheeks.

‘Marshal Blücher!’ Arthur called out at once, raising his hand.

The Prussian officers turned towards him and as he reined in Blücher recognised Arthur in turn, edged his mount over and embraced him. Neither man spoke the other’s language, and Blücher blurted out, ‘Mein lieber Kamerad! ’ And then, in a guttural accent, ‘Quelle affaire!’

Arthur laughed and clapped him on the shoulder. ‘Bonaparte is beaten. Once and for all.’ He paused and shook his head. ‘But it was a damned close run thing!’

The pursuit continued after nightfall. Arthur’s troops were too exhausted to go far and gradually abandoned the task to the Prussians. A pale moon rose over the battlefield and cast a ghostly silver-grey hue over the fields of death where the bodies of tens of thousands lay stiffening in the cool air. The ride along the road back to Waterloo filled Arthur with a numbing sense of unreality. The air over this same ground had earlier been filled with the deafening roar of guns, the crack of muskets and the rhythmic signals of bugles and drums.

It was quiet now, but far from silent. Many of the wounded lay groaning, crying out or simply talking to themselves. Some babbled incoherently, driven mad by pain or the trauma of the day’s experiences. Here and there small parties of soldiers searched for wounded survivors of their regiments to carry back to the dressing stations behind the ridge and in the village of Waterloo. The defenders of Hougoumont had emerged from their strongpoint and left the fire in the barns to burn itself out, the flames still casting a glow across the bodies piled around the house and gardens.