Bernadotte frowned irritably. ‘I judged that it would be best to continue with my existing orders rather than cause any delay in my corps’s movement by rerouting the line of advance towards Davout. It was a professional judgement, sire. If you wish to hold me accountable for anything, then let it be for making an unfortunate decision for the right reasons.’

Napoleon stabbed a finger towards him. ‘There was nothing professional about your judgement.You disobeyed an order.You endangered Davout and his entire corps and the snail’s pace of your advance towards Dornburg makes even the Prussians look quick-witted by comparison.’>

Bernadotte shrugged dismissively. ‘There were certain difficulties along the route.’

‘That is a lie. I have had an officer retrace the route and he can find no explanation for the tardiness of your advance.’

‘The officer was not there on the day, sire. What could he know of the difficulties faced by my men? The roads were narrow and we were obliged to halt frequently to drive off enemy scouts.’

‘Good God, man! If the army stopped to fight every scout it encountered we would never advance far beyond the borders of France.’ Napoleon slapped a hand down on the table. ‘Your excuses are feeble, Marshal Bernadotte.You are guilty of a gross dereliction of duty and I can tell you that there is a widespread feeling in the army that you must be called to account, and punished severely.’ Napoleon reached into his breast pocket and pulled out a document and placed it in front of him. ‘Do you know what this is? An order for your court-martial. I have already signed it.’

Bernadotte stared at the document and for the first time his arrogant composure slipped and Napoleon saw a flash of anxiety in his expression.

‘You mean to court-martial me?’

‘The army is expecting it,’ Napoleon replied coldly. ‘You deserve no less. I dare say that any trial before your peers would find you guilty.The other marshals would support such a verdict, and order that you be shot.’

Bernadotte bit his lip. ‘You would countenance that?’

‘If that was the verdict of the court, what else could I do? I will not side with you against the will of the Grand Army.’

Bernadotte took a half-step towards the table and gestured in the direction of the signed order.‘Sire, this is absurd. I am no traitor. I would never betray the interests of France. I am your loyal servant, and I am married to the sister of your brother Joseph’s wife.’

It was a desperate gambit, and Napoleon could not help feeling contempt at such a naked appeal to place family concerns before national interest. He stared back at the miserable Bernadotte and let him suffer through a prolonged silence before he spoke again.