Alicky was seized by panic. Until now, all her thoughts about the ball had centred solely on Nicky: on how he would hold her in his arms and, beneath glittering chandeliers, waltz her round and round to the heavenly music of Glinka and Tchaikovsky. Now reality was sinking in. In order to enjoy the bliss she had dreamed about for so long, she was going to have to endure being the focus of many more pairs of eyes than she had expected. She steadied her breathing, forcing herself to remain calm. If she had to suffer an evening of such torture so that she could be held in Nicky’s arms, then it was a price she was willingly going to pay.

Nothing she had ever experienced before – not at home in Darmstadt, or at Buckingham Palace or Windsor – had prepared her for the sheer size and splendour of what lay ahead.

Velvet-carpeted corridors were lined every step of the way by scarlet-uniformed Cossacks; the galleries opening onto the Nicholas Hall, where the ball was to be held, were each as high and vast as a cathedral, a vista of soaring gold-framed mirrors, glistening marble columns and priceless statues. Beneath the shimmering light of crystal and gold chandeliers, Russia’s royalty, aristocracy, court officials and senior members of the country’s navy and army greeted each other and, as they waited for the entrance of the Tsar and Tsarina, exchanged the latest gossip, looking towards Alicky with blatant curiosity as they did so.

She was already well aware of how popular Ella was in St Petersburg. What she hadn’t taken into account was how much interest there would be in her, simply because she was Ella’s sister.

‘Smile, Alicky,’ Ella instructed, not letting the smile on her own lips slip for an instant. ‘Let people know how happy you are to be in St Petersburg.’

Alicky was happy to be in St Petersburg, but she wasn’t happy at being the centre of attention. Instead she was petrified and far too frozen with panic to emulate Ella’s easy, gracious smile.

And then salvation came. The Master of Ceremonies brought the Nicholas Hall to an instant hush by striking the floor with a golden-topped staff and then, having called for silence, announcing thunderously, ‘Their Imperial Majesties!’

Every woman in the room, Ella and Alicky included, sank into a curtsey as the Tsar and Tsarina entered the ballroom and then, as Alicky stood straight again, she saw with stupefying relief that Nicky was only a few steps behind his parents.

His eyes sought and found hers, and she read the message in them clearly: Etiquette decrees that you dance first with your father and then with Sergei, whose personal guest you are, and then with your brother. Then, and only then, will it be proper for us to dance together.