The troop fell in behind the general, bits jingling, hooves clattering on the dry road, and John, with a delicious sense that he should not be tagging on as a spectator, followed behind with Caesar pulling at the reins, his neck arched and tail held high at the prospect of action.

When they reached Scotland Yard at the side of the Palace of Whitehall he saw that the trooper was right, and his sense that he would have been safer to go straight home was right too. It was going to be an ugly scene, a pitched battle between the Parliamentary Horse Guards and Lambert’s regiments at the very gateway to the Houses of Parliament. John reined back Caesar, who pulled against the bit as if he too knew that fighting was likely and was ready for the charge.

‘Halt!’ commanded Lambert and his personal standard dipped to show the signal. The troop of horse halted with a clatter of hooves on the cobbles.

The regiment before the Houses of Parliament tightened their grip on their pikes, blew on the fuses of their muskets and waited for the order to fire. A horse in Lambert’s regiment moved restlessly against a too-tight rein, and the chink of the bit was very loud in the silence. There was a long pause as one English regiment eyed another and waited for the command to attack.

John could hear his breathing light and rapid as he sat in the saddle. Any moment he thought he would see the muskets lifted and hear the dreadful crack of their firing. There were probably cannons nearby too, and the Parliamentary Horse Guards had the advantage of being in defence, and near to the stout walls of Whitehall, while Lambert’s men were drawn up in the road.

There was a long, long pause as the two troops faced each other, then John Lambert slid from his saddle and dropped to the ground, his spurs ringing as they tapped the cobblestones. He tossed his bridle to his standard bearer and walked forwards as if he were strolling in his orange garden. He left the sheltering ranks of his men, and out across the cobbled gulf which separated the two regiments, as if the men on the other side were not poised to take aim, as if they were not waiting for the order to shoot him down. He smiled at them as if they were his own regiment, his own trusted men. He smiled at them easily and pleasantly, as if he were glad to see them, as if he were greeting them as old friends.

‘My God, what is he going to do?’ John whispered to himself.