The Earl shared the image on his Instagram page this week, writing, “My first day of school, in September 1968: my father took this photograph of me and my sister, Diana, just before he drove us to Silfield, a really lovely primary school in King’s Lynn, Norfolk. The headmistress was Miss Jean Lowe, a warm and thoughtful lady who loved her boys and girls…I was there till 1972, when I headed off to the place I call—in my memoir—A Very Private School.”

In the photograph, Diana can be seen standing next to Charles, the two dressed in matching red blazers, red ties and long gray socks. The snap would have been taken when Diana was seven-years-old, while Charles would have been just four.

Charles Spencer shared a previously unseen picture of himself with his sister Diana this week.

Instagram @charles.earl.spencer

Many of his followers were struck by how similar the late Princess of Wales appeared to her granddaughter, Princess Charlotte. The little royal will be turning nine at the start of May—and with her mousey brown hair and pretty blue eyes, it isn’t hard to see why many see a family resemblance between the two.

One person commented, “Princess Charlotte is Diana’s copy.” Another wrote, “Princess Diana lives on in William’s children. The resemblance is wild.” A third added, “William’s children are definitely Diana’s copies.”

Princess Charlotte, pictured with Kate Middleton at the Christmas Day service.

It is not the first time that Charlotte has been said to have a family doppelgänger. She has previously been said to look like Lady Kitty Spencer, her grandmother’s niece, and Lady Sarah Chatto, the Queen’s niece and daughter of Princess Margaret. She’s also been compared to the late Queen Elizabeth II—her great-grandmother—when she was a girl.