The Queen watched on as her granddaughter Princess Beatrice married her fiancé Edoardo Mapelli Mozzi, but she was one of the first guests to leave after the ceremony.
The couple tied the knot in secret at All Saints Chapel this morning, in front of a small group of family and friends.
The Queen and Prince Philip were seen leaving the ceremony just 45 minutes after it began, smiling as they drove back to Windsor Castle.
It has been reported that the Queen left promptly after the ceremony as she wanted to get back to get ready to present Captain Tom Moore with his knighthood.
Captain Tom, who turned 100 in April, raised nearly £33million for health service charities by walking laps of his Bedfordshire garden.
The investiture is her first official engagement since the coronavirus lockdown was introduced.
She was seen in public for the first time since lockdown on June 13 when she attended a stripped back Trooping the Colour.
And that’s not the only nod to Captain Tom, and Beatrice and Edo have decided not to release an official wedding photo today as they don’t want to take the spotlight off the fundraising hero.
This afternoon, Captain Tom and his family will travel to Windsor for the special, personal service.
Royal investitures were put on hold during the pandemic, and those scheduled to take place at Buckingham Palace and the Palace of Holyroodhouse in Edinburgh in June and July were postponed.
The ceremony will take place entirely within the confines of Windsor Castle, with no viewing positions for the public.
Members of the public are being asked not to attend Windsor town centre or gather in the hope of seeing any of the ceremony, which will not be visible from any external viewpoint.
The Queen will use the sword that belonged to her father, George VI, and will present him with the insignia of Knight Bachelor.
Captain Tom had set out to raise £1,000, but his incredible gesture won him fans around the world and saw his fundraising efforts soar.
In honour of his incredible achievement, he was given a flypast on his 100th birthday.
Captain Tom also became the oldest person to ever score a UK Number One single with his rendition of You’ll Never Walk Alone, recorded with Michael Ball and the NHS Voices Of Care Choir.
And his incredible efforts saw him awarded a special Pride Of Britain award.
Captain Tom said the response to his charitable efforts had been “outstanding”.
He said: “It’s hard to describe there’s been so much kindness shown and so many people making kind remarks.
“It really is outstanding, I never anticipated in my life anything like this. It really is amazing.
“I really must say to everyone thank you very much to everyone wherever you are.”