BRITAIN鈥檚 William, Prince of Wales; Catherine, Princess of Wales; Britain鈥檚 Prince Harry and Meghan, the Duchess of Sussex, walk outside Windsor Castle, following the passing of Britain鈥檚 Queen Elizabeth, in Windsor, Britain, Sept. 10. 鈥 REUTERS

WINDSOR 鈥 Prince Harry and his wife Meghan joined William and wife Kate on a walkabout among crowds near Windsor Castle on Saturday following the death of their grandmother Queen Elizabeth II, raising the prospect of a rapprochement between the brothers.

The two sons of King Charles, once so close after the death of their mother Diana in a Paris car crash in 1997, have fallen out in recent years after Harry and Meghan gave up their royal titles to move to the United States.

The couple had been in Britain on a brief visit when the queen, Britain鈥檚 longest reigning monarch, died on Thursday.

Like other senior members of the royal family, Harry rushed to be by the queen鈥檚 side as she deteriorated at Balmoral Castle in Scotland, and a spokesperson for the heir to the throne said an invitation for the Windsor walk had been extended by William.

A royal source described it as an important show of unity at an incredibly difficult time for the family. They emerged from the same car, all wearing black.

The two couples did not interact much during the 40-minute walkabout near one of the queen鈥檚 favorite English homes, as they stopped to read messages left among the flowers, and shake hands and chat with the thousands of people lining the Long Walk.

鈥淚 think that really just sort of draws a line under what鈥檚 happened historically, and it鈥檚 a really strong sense of unity I think for the royal family. It was really lovely to see,鈥 said Raj Kaur, 41, who was in the crowd.

At one point Meghan was hugged by a woman in the crowd while others stretched to shake hands and talk to the four royals in the early evening. William spent some time bending down chatting to children, while Kate and Harry accepted flowers and messages of encouragement from those in the crowd.

Royal observers had been looking for signs of a detente amid the pomp and ceremony of a period of national mourning and Elizabeth鈥檚 state funeral.

On Friday Charles used his first address to the nation as king to express his 鈥渓ove for Harry and Meghan as they continue to build their lives overseas鈥.

He also bestowed on William and daughter-in-law Kate the titles of Prince and Princess of Wales, which he and his late wife Diana previously held.

William was heard telling one well-wisher that the days following the queen鈥檚 death had been 鈥渟o surreal鈥.

鈥淲e all thought she was invincible,鈥 he said.

Asked by someone else in the crowd how his children, George, 9, Charlotte, 7, and Louis, 4, who all started at a new school on the day the queen died 鈥 were coping, he replied: 鈥淭he kids are well, thank you. They are good. Not ideal to start new schools with everything happening.鈥

Under royal rules, the monarch鈥檚 grandchildren are automatically eligible to become princes or princesses of the realm, so now that Harry鈥檚 father Charles is king, his children, Archie, 3, and Lilibet, 1, can receive those titles. Lilibet was named after the queen鈥檚 childhood nickname.聽

It is not clear whether they will take the titles.

鈥淎t the moment we鈥檙e focused on the next 10 days. As and when we get information, we will update the (royal) website,鈥 a spokesperson for Charles told reporters. 鈥 Reuters