The South Africans have built a special train for the tour. Elizabeth gasps when she sees it. With its fourteen carriages painted ivory and white, each decorated with the royal crest, The White Train gleams in the brilliant light as it streaks through the spectacular landscape. It curves around hills and mountains, arrows across the dusty veldt. She writes to Philip every evening.

We each have our own bedroom and bathroom. There is a drawing room and a dining room, and Papa has a study and Mummy has her own sitting room. All on the train! There is even a post office, which I will use to send this letter to you, and a telephone exchange which is connected at the main stops so Papa can keep in touch with events at home.

I know you have been to South Africa so I don’t need to explain how beautiful the country is but I have never seen such light before. So different from the lovely Scottish summer light. Here it is diamond hard and it outlines every tiny thing so sharply that I keep having to blink.

Elizabeth pauses, her pen still in her hand, as she looks out at the veldt. It stretches away to a distant horizon where the sky is flushed a deep red barred with strips of purple cloud. Her bedroom on the train is furnished with a desk at the window and when the train has stopped for the night, as now, she likes to sit and write to Philip.

The view is distracting though. She keeps stopping to stare at the stupendous scale of it. The train has rumbled across endless stretches of golden grassland all day, broken only by the occasional acacia tree or the glimpse of mountains in the far distance. She and Margaret hung out of the window to watch a herd of zebras galloping away from the train.

Dipping her pen in the ink, Elizabeth returns to her letter to tell Philip about the wildlife they have glimpsed.

We saw some giraffes today, too. They are such extraordinary creatures and it was exciting to see them in the wild. They kept their distance but didn’t seem too bothered by the train but turned their heads to watch us as we went by.

Sometimes we see people, too, just standing with their horses by the side of the track in the middle of nowhere, waiting to wave at us. Peter (do you remember Papa’s equerry?) says that some of them may have ridden more than fifty miles to see us. I always feel terrible if we don’t see them in time to wave back. Everyone in South Africa has been so very welcoming. If I didn’t feel guilty knowing how much people at home are suffering in the winter, I would be loving it – although I do wish you could be here too.

I don’t think Mummy and Papa are enjoying the tour so much. Everything is new and exciting for Margaret and me but for them it is quite wearing and poor Papa in particular finds it exhausting. He doesn’t like the way the Afrikaner police order us around at times. He calls them the Gestapo. I’m afraid his temper is on a very short fuse.