The princess and Philip wrote to each other regularly and the enforced separation did nothing to dampen their love. On the contrary, it intensified it. Luckily for her, the trip was packed with engagements, and her days and evenings were filled with receptions, dinners, train journeys and welcomes, culminating in her twenty-first birthday speech in Cape Town, given in the gardens of Government House. It was crafted by leader writer and court correspondent of The Times, Dermot Morrah. The princess spoke from her heart to the youth of the whole Empire and her words had the impact they were intended to make: ‘I declare before you all that my whole life, whether it be long or short, shall be devoted to your service and the service of our great imperial family to which we all belong. I shall not have the strength to carry out this resolution alone unless you join with me, as now I invite you to do.’ Queen Mary was so moved by her granddaughter’s words she confessed she ‘wept’ when she heard it on the radio.

After the family’s return, Prince Philip told the Queen that although he realised she had been right to persuade them to delay the announcement, now he and the princess wanted to start their new life together, and in their absence he had been doing all he could to ensure that all objections were removed. In February, he had become a naturalised British subject, thus Prince Philip of Greece became Lieutenant Mountbatten RN. The Archbishop of Canterbury wrote to the King suggesting that Philip, who had been baptised in the Greek Orthodox Church, be officially received into the Church of England, and by October that was concluded.

Even so, the princess’s parents still admitted to their concerns, as is typical for anyone when the time comes to give away their daughter in marriage. ‘You can imagine what emotion this engagement has given me,’ the Queen wrote to Tommy Lascelles. ‘It is one of the things that has been in the forefront of all one’s hopes and plans for a daughter who has such a burden to carry, and one can only pray that she has made the right decision, I think she has – but he is untried yet.’

In July, the Queen wrote to her sister, May (Lady Mary Elphinstone, mother of the Hon. Margaret Rhodes), to tell her very secretly that Lilibet had ‘made up her mind’ to become engaged to Philip Mountbatten. ‘As you know she has known him since she was 12 and I think she is really fond of him and I do pray she will be happy.’ They were keeping it ‘a deadly secret’ because she didn’t want the press finding out and ‘ruining everything’.