The Duchess of York is said to have rekindled her romance with her former husband, the Duke of York.
Friends claim the couple are so close that they will eventually formalise their reunion.
"Mark my words, they will remarry," said one friend. "It is only a matter of time."
Another said: "It wouldn't surprise me at all. They are a wonderful couple together and, better still, pretty amazing parents."
The couple have remained close since they divorced in 1996 and both live at Royal Lodge, the former country home of the late Queen Mother, in Berkshire. They joined their children, Princess Beatrice, 25, and Princess Eugenie, 23, for the weekend at Balmoral, the Queen's Scottish retreat, this month.
The Duchess, 53, was at Balmoral in 1992 when a tabloid newspaper published photographs of her having her toes sucked by John Bryan, her "financial adviser".
She had not been invited back to the castle until this month.
In little-noticed comments in 2009, Prince Andrew, also 53, said he did not rule out remarrying the Duchess.
"Do we have to be married?" he asked. "Well, let's put it another way, I can neither confirm nor deny the possibility. We have two great children. We still look after them."
The Duke has been linked to a string of women over the years, but none of the relationships has endured. The Duchess' friendships have similarly faltered.
In 1999, the Duchess said: "There was no reason for Andrew and I to get divorced; there wasn't another person in our lives to go to.
"We got divorced because I had to go out to work, and Andrew and I believed that it wasn't right for me to be commercial while I was still in the royal family.
"I had to provide for my children, but not do it on their own doorstep in this country, rubbing the royal family's noses in my commerciality."
Prince Andrew has never criticised his former wife and has provided financial support when she has needed it.
A spokesman for the Duchess declined to comment.