Matt Smith says Prince Harry called him 'Granddad' after playing Prince Philip in The Crown

The royals are known to have a brilliant sense of humour, and over the years fans of the family have learnt about the practical jokes that they play on each other behind closed doors - from the trick that Princess Diana once played on Prince William, to the present that Kate Middleton once bought for Prince Harry at Christmas.

There's also the amusing anecdote about the Queen herself pranking tourists while she was out enjoying a country walk.

And it seems that Prince Harry had a comical reaction to meeting actor Matt Smith, who famously played the Prince Philip in The Crown.

Smith took on the role of the Duke of Edinburgh in 2016, playing the royal for the first two seasons alongside Claire Foy as Queen Elizabeth II.

While many have speculated about whether or not the real royals watched the popular Netflix series, it appears that the Duke of Sussex is certainly familiar with it.

During an interview on Today, Smith was talking about playing Daemon Targaryen in House of the Dragon - which is currently airing on Sky Atlantic - when his former regal role came up in conversation. He revealed that after playing Prince Philip in The Crown, he happened to meet Harry at a polo match.

He told the hosts: 'I met Harry once, at polo, which sounds a bit grand, but it wasn’t that grand.

'And he walked up to me and went, "Granddad."'

Smith continued: 'He watched the show! Well, I can’t claim to know if he watches it currently, but he watched a bit of it then.'

As to whether or not the Duke of Edinburgh and the Queen ever watched the show, Smith said: 'I heard the Queen had watched it, and she used to watch it on a projector on a Sunday night apparently.

'I know that Philip definitely didn’t. A friend of mine sat next to him at a dinner once and he asked him... apparently he turned around to him and said: "Don’t be ridiculous".'

So there you have it!