As they strolled through the sea of well-wishers, exchanging greetings with the crowds at Sandringham, who could have seen how rough the waters were about to become.
Within months of their joining the Royal Family for their time-honoured appearance at the Christmas Day service at a tiny Norfolk church in 2017, the tide would turn for Harry and Meghan.
The set-piece photos outside church are full of smiles. But behind the scenes, things would soon turn ugly, Meghan revealed during Oprah Winfrey's hour-long exclusive interview with the couple.
In May, the couple married - in secret, three days before they officially tied the knot at Windsor, we learn from the programme.
And while we knew life inside the Firm is very different to how the rest of us live it, the picture that emerges is one of a court of control freakery which left the newly-weds feeling trapped and unsupported as the tabloids turned on them.
Rumours of a rift between the Sussexes and the Cambridges up at Anmer Hall were swirling the following year before the couples once again joined the royals for Christmas Day at Sandringham.
Meghan made Kate cry in a row over bridesmaid's dresses before her and Prince Harry's wedding, according to unnamed sources. Now Meghan says it was the other way round: Kate made her cry, but said sorry and has been forgiven.
The duchess says she was promised protection from more aggressive sections of the media but this never materialised as the headlines got darker.
Regardless of who made who cry, you'd never had thought there was a problem after another set-piece walk to church, with the Sussexes and Cambridges walking side by side.
It goes with the territory, Prince Harry told Oprah. Whatever's going on behind the scenes, you have to dry your eyes, get out of the car and be on your 'A Game' when you meet and greet the public.
December 25 is often the only day of the year when the Queen and all of her immediate family are seen together. Future years will see a smaller gathering now the Sussexes have pretty well burned their bridges with the monarchy.
The Sussexes' future and their stepping back from royal life was discussed at the so-called Sandringham Summit on January 13, 2020, when Prince Harry travelled to Norfolk for talks with the Queen, Prince Charles and Prince William.
But in footage not included in the Oprah Winfrey interview, which has now been broadcast by US Network CBS, Harry reveals he was invited for a private chat with the Queen a week beforehand, which was subsequently cancelled.
Harry said the Queen had told him to come and see her there after he and Meghan arrived back in the UK from Canada.
He said: "My grandmother had said 'the moment you land, come up to Sandringham, we'd love to have a chat, come for tea, why don't you stay for dinner because it's going to be a long drive and you're going to be exhausted?"'
He said "the moment we landed in the UK" he got a message from his private secretary at the time, passing on a message from the Queen's private secretary.
He said it was "basically saying 'please pass on to the Duke and Duchess of Sussex that he cannot come to Norfolk. The Queen is busy, she's busy all week'."
Royal watcher Mary Relph, 87, is a regular at Sandringham on Christmas Day. She won't be too upset if the Sussexes stay in America next year.
"I was very shocked and disgusted by the comments made about the Royal Family," she said. "They welcomed her with open arms when she came over here.
"I think it's terrible. The Queen should strip them of their title, let them stay in the US and let them earn their own money."
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