Talleyrand shook his head.‘He would be arrested, or assassinated, the moment he set foot on French soil. I agree, he will go to Italy. He has friends there, and family. Napoleon will go to Murat.’

‘Even though Murat betrayed him last year?’ Metternich queried.

‘I imagine he will ask his brother-in-law for asylum,’ Talleyrand suggested. ‘I know him, I know his strength of will. He is a hard man to refuse. Murat will take him in. Then, when the moment is ripe, Napoleon will seize power. The kingdom of Naples will be his new base of operations.’

It made some sense,Arthur reflected. Murat’s domains would provide him with an army large enough to threaten the rest of the Italian kingdoms.

The Tsar cleared his throat and leaned towards the conference table. ‘The question is, gentlemen, what shall we do about this?’

Talleyrand looked at him with a faintly surprised expression. ‘Do, your majesty? Why, we should organise an army to march on Napoleon and crush him, before he has time to prepare. That much is obvious. Meanwhile, the Congress must continue. The peace settlement is more important than the pursuit of a criminal, however notorious.’

The other delegates nodded their agreement, but Arthur was not so certain. He had witnessed the strong loyalties that Bonaparte still commanded in Paris. If the former Emperor raised his banner in Naples, then many thousands would flock to join him, and those who remained would be sure to unsettle the new regime in France.

Over the next few days messages were sent out from Vienna to mobilise the allied armies. The audacity of Bonaparte’s escape had shocked the delegates, but there was little sense that he posed an immediate danger to Europe, and the powers continued their deliberations as they awaited confirmation of his location. It was four days after Colonel Campbell broke the news of his disappearance that the truth was learned. One of Talleyrand’s aides entered the chamber just before the midday recess and whispered urgently in his ear. Arthur watched as the French Foreign Minister’s face drained of blood. Metternich was speaking, reading verbatim from notes, and had not noticed the little drama.

Talleyrand rapped his knuckles sharply on the table and the Austrian minister looked up irritably, stopping his address mid-sentence.

‘Pardon my interruption,’ said Talleyrand as he looked round the table, ‘but I have just been informed that Napoleon landed on the coast of France six days ago. He has declared that he has come to reclaim his throne and is marching on Paris.’

There was a moment’s stunned silence, then Arthur spoke. ‘Did the local authorities oppose him?’

‘On the contrary. I am told that they went over to him without a shot being fired.’