Prince Harry and Meghan Markle secretly visited the Queen and Prince Charles on a trip to the UK.
The Duke and Duchess of Sussex jetted in today from the US for the face-to-face with the monarch at Windsor Castle.
They also saw the Prince of Wales during the whistle-stop trip on their way to Holland for the Invictus Games.
The couple, who snubbed the chance to attend the late Prince Philip's memorial service last month, smiled and waved at the stunned onlookers.
Members of the public were in the grounds of the royal estate for the traditional Maundy Thursday ceremony.
There have been mounting tensions between the pair and the rest of the royals due to a series of scandalous claims made from across the pond.
The surprise appearance comes amid Harry's ongoing legal action against the Home Office after it refused to supply him with armed bodyguards during any future visits to Britain.
The Duke is suing the government department and claims he "does not feel safe in the UK".
Ingrid Seward, editor-in-chief of Majesty Magazine, described the visit as the offering of an "olive branch" and "wonderful opportunity to clear the air".
She said: “After everything that has gone on it must have taken a lot for Harry and Meghan to go to Windsor."
The expert added that Maundy Thursday is a very special day for the Queen and is "about forgiveness", with the monarch "not one to hold grudges".
Ms Seward believes she would have "happily welcomed them with open arms".
It is unclear if Archie, two, and 11-month-old daughter Lilibet joined their parents or if they are back home in Montecito.
It's the first time both Harry and Meghan have been back in the UK together since they left two years ago.
Harry flew back for his grandfather Philip's funeral in April last year, but a then-heavily pregnant Meghan had been warned against the trip by doctors.
The duke was also back last July to join brother Prince William for the unveiling of a statue of their late mum Princess Diana.
A Windsor visitor who clocked the couple on Thursday told the Sun: "They looked happy and relaxed and waved to everyone on the bus.
"It was quite the sight. We knew we might see Charles and the Duchess of Cornwall at the ceremony but never believed we would bump in to Harry and Meghan."