The Queen and Prince Philip have been married 70 years. So why does The Crown 2 focus on his "affairs"?

Queen Elizabeth and Prince Philip are celebrating their 70th wedding anniversary – a milestone that makes them the longest-married royals in British history.

The pair were married on November 20, 1947 and have released a series of new portrait images to celebrate, in which they are smiling together. At least from the outside, this looks like a happy marriage, that has withstood the many external and internal potholes that come with any long-term relationship.

So why then have the creators of Netflix’s The Crown decided to focus on what may or may not have almost ruptured this marriage in its upcoming season?

LISTEN: Clare and Laura recap The Crown Season 2 on the latest episode here 

Two teaser trailers, one of which includes interviews with the cast and crew, have given us a glimpse of what The Crown will feature in its second season – and by the look of it, Prince Philip’s alleged wandering eye will be a focus.

Actress Claire Foy, who plays Queen Elizabeth II can be heard saying to her on-screen husband Matt Smith in one part, “This restlessness of yours it has to be a thing of the past. The monarchy is too fragile, you keep telling me yourself. One more scandal, one more national embarrassment and it would all be over.”

Interspersed with shots of Philip looking at beautiful women, we also see the Queen telling Philip, “The rumours haven’t gone away. I think we both agree it can’t go on like this.”

And finally, she tells someone unseen on-screen, “There is no possibility of my forgiving you. The question is how on earth can you forgive yourself?”

While it is not clear that Foy as the queen is addressing Smith’s character with this final statement, these snippets, along with others and cast comments suggest the Prince’s “restlessness” will be portrayed on screen.

But the true extent of the restlessness the real Prince Philip experienced is up for debate.

It’s been confirmed by many that the Duke of Edinburgh had a weekly gentlemen’s lunch club in the Soho area of London, with many suggesting this was a way for him to blow off steam, as he felt to some extent emasculated by his position as the queen’s husband.

According to a 1996 account from one of the club’s members Miles Kington printed in The Independent, there were plenty of women, mainly waitresses from various pubs, present at the club’s Thursday lunches, but did not speak of anything untoward happening between them and the men present.

Various biographers were the ones to tackle Philip's alleged affairs, exploring his links to women including friend Penny Brabourne, television personality Katie Boyle and British actress Pat Kirkwood. None were able to concretely verify the rumours or the claims of one biographer who went ahead in accusing Philip of affairs. Certainly, the palace and Philip himself only denied the claims on the rare times they addressed them.

"How could I? I’ve had a detective in my company, night and day, since 1947," Philip is quoted as saying in response to questions of alleged affairs.

Regardless of how true rumours at the time might have been, there's no doubt the royal marriage has survived any turbulence.

Now, and as long as many of us have been alive, the Queen and her husband have put forward an image of a happily married couple, who dote on and care for one another.

And perhaps that's why The Crown has decided to zero in on the tensions and cracks that may have set in and later been patched up. Because it's the side of the royals we don't normally see that Crown fans keep coming back for.

You can watch The Crown, Season 2, on Netflix from December 8.