Prince Charles reportedly shares a surprising link with his dad, Prince Philip.

Before retiring two years ago, the Duke of Edinburgh has been an advocate for climate change. Prince Charles has also been very passionate about the issue, and it was one of the things he discussed with President Donald Trump during his visit to the United Kingdom last week.

But it seems that their focus on climate change is just one of the few things that the royals share in common. Growing up, Prince Charles couldn’t be more different from his dad.

During an interview in 2016, Prince Philip told Gyles Brandreth that his personality is very different from the personality of his eldest son.

“He’s a romantic and I’m a pragmatist. That means we do some things differently… And because I don’t see things as a romantic should, I’m unfeeling,” he told Radio Times.

Growing up, Prince Philip was also quite stern and distant towards Prince Charles because he noticed early on that his son was quite soft. But multiple sources have said that this may be because the Duke’s upbringing was also quite strict.

When he was just a young boy, Prince Philip’s mom, Princess Alice of Battenberg spent some years in an asylum due to his schizophrenia. It was only when Queen Elizabeth II’s husband was already in his 20s that he managed to spend some time with his mom.

And while Princess Alice was away, Prince Philip’s dad was having an affair with another woman. As such, the retired royal grew up without a father figure in his life.

Meanwhile, another thing that caused strained in Prince Philip and Prince Charles’ relationship was the fact that the former picked favorites – and it’s not the latter.

Prince Philip was much closer to Prince Charles’ younger sister, Princess Anne because they are more alike. The Duke was also very close to Prince Edward because they are tough and witty.

Prince Charles, Prince Philip
Princes Charles, Philip is greeted by his son Prince Charles, Prince of Wales as she arrives at the funeral service of Patricia Knatchbull, Countess Mountbatten of Burma at St Paul's Church in Knightsbridge on June 27, 2017 in London, United Kingdom. Getty Images/Matt Dunham-WPA Pool