Prince Harry and Meghan Markle joined the royal family as Queen Elizabeth II's coffin was received at Buckingham Palace Tuesday after departing the RAF Northolt Airforce station in Ruislip, England. 

Queen Elizabeth II died Thursday at the age of 96. She was the longest-reigning monarch in British history, and the second longest-reigning monarch in the history of the world. 

The hearse arrived to cheers outside of Buckingham Palace as the streets of London were lined with mourners.

Prince William and Kate Middleton, who were recently appointed the Prince and Princess of Wales, were also seen arriving at the palace.

KING CHARLES III RECEIVES QUEEN ELIZABETH II'S COFFIN AT BUCKINGHAM PALACE IN LONDON

Prince Harry and Meghan Markle

Prince Harry and Meghan Markle arrived at Buckingham Palace to receive Queen Elizabeth II's coffin with royal family members, including King Charles III and Prince William. (Guy Bell/Shutterstock)

Meghan and Harry sat in the back seat as they were driven to the palace ahead of the arrival of the Queen's coffin, which will rest in the Bow Room overnight until being moved into Westminster Hall to lie in state. Hundreds of thousands of mourners are expected to file past and pay their respects to Her Majesty before her official funeral Monday.

The Duke and Duchess of Sussex have now reunited with Prince William and Kate twice since the Queen's death Thursday, and were coined the "Fab Four" following a public viewing of floral tributes outside of Windsor Castle on Saturday.

PRINCE WILLIAM, KATE'S BODY LANGUAGE IS ‘GIGANTIC DIFFERENCE’ FROM ‘AFFECTIONATE’ PRINCE HARRY, MEGHAN: EXPERT

Body language expert Tonya Reiman exclusively told Fox News Digital there was a "gigantic difference" between the couples, which began in the way "they approached one another" and carried on throughout the long walk as Harry lovingly held his wife's hand while the newly-appointed Prince and Princess of Wales acted more like "royals" with distance between the pair.

"People were going, ‘Oh My God, you see how much love there is between one couple [Harry and Meghan], but the other couple [William and Kate] are royals.’ They're used to this stuff," Reiman said. 

As they made their way to the crowds, the "difference is definitely obvious when you come to Meghan" who was warm and welcoming, offering hugs and speaking with members of the public as if they were her own family. At one point, it appeared as though Meghan promised to bring flowers to The Queen's resting place, but an aide insisted Markle hand over the blooms and continue meeting with the people.

Prince Harry and Meghan Markle in private car

A vehicle carrying Prince Harry, Duke of Sussex, and Meghan, Duchess of Sussex drives toward Buckingham Palace to receive Queen Elizabeth's coffin on September 13, 2022 in London, England.  (Dan Kitwood)

Prince William and Kate Middleton travel to Buckingham Palace

Prince William and Kate Middleton reportedly traveled in a separate vehicle to join the royal family as Queen Elizabeth's coffin arrived at Buckingham Palace in London.  (Dan Kitwood)

Queen Elizabeth II hearse

The coffin of Queen Elizabeth II arrives in the Royal Hearse at Buckingham Palace in London on September 13, 2022, where it will rest in the Palace's Bow Room overnight. (Justin Tallis/AFP)

queen jaguar hearse

Queen Elizabeth II's coffin traveled to Buckingham Palace Tuesday.

Reiman commented that the differences were more evident than ever when Harry ran to open the car door for Meghan while William stood aside as Kate handled the situation alone. "You become comfortable with what you know and expect," she said.

PRINCE WILLIAM, PRINCE HARRY, KATE MIDDLETON AND MEGHAN MARKLE, THE FAB FOUR'S ROCKY RECENT HISTORY

"William is just completely royal and has a 'don't get too close to me' persona. So I think Harry wants to be the person who gets close, but can't because of how he's been brought up. He tries, but you can always see that there's something stopping him and again, I don't think that's a conscious thing. I think he tries but he can't. When you look at William, I think that it's more of a 'this is the line that we draw in the sand, and you can't cross it.'"

Prince Harry broke his silence on the passing of his "Granny" in a tribute written Monday dedicated to how "globally admired and respected" Her Majesty was, with "unwavering grace and dignity."

Posted to the Archewell Foundation's website, the Duke of Sussex wrote, "Granny, while this final parting brings us great sadness, I am forever grateful for all of our first meetings—from my earliest childhood memories with you, to meeting you for the first time as my Commander-in-Chief, to the first moment you met my darling wife and hugged your beloved great-grandchildren."

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Prince William and Prince Harry with their wives, Kate Middleton and Meghan Markle

Kate Middleton and Prince William were far less affectionate with each other while greeting the crowds outside Windsor Castle on Saturday, according to a body language expert. (Chris Jackson)

Princess Anne released her first statement regarding the death of her mother. She traveled with the coffin from St Giles' Cathedral to Edinburgh airport, which was then transported by hearse to Buckingham Palace.

"I was fortunate to share the last 24 hours of my dearest Mother’s life. It has been an honour and a privilege to accompany her on her final journeys," the Princess Royal wrote. "Witnessing the love and respect shown by so many on these journeys has been both humbling and uplifting. We will all share unique memories. I offer my thanks to each and every one who share our sense of loss."

"We may have been reminded how much of her presence and contribution to our national identity we took for granted," she added. "I am also so grateful for the support and understanding offered to my dear brother Charles as he accepts the added responsibilities of The Monarch."

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