Why Kate Middleton Was Rendered “Speechless” and in “Total Shock” by Prince William’s Proposal, According to Royal Author

Even though they had been together for almost a decade when they got engaged, Kate Middleton reportedly still didn't Prince William's proposal coming.

Royal expert and author Katie Nicholl detailed the days leading up to the couple's romantic engagement moment in her book Kate: The Future Queen, in which she explained that when the couple traveled together to Kenya in October 2010, Kate actually had "dared to hope that she might return from Africa with a ring on her finger."

That changed, however, as the vacation went on and, according to Nicholl, by the last day, "Kate had given up hope" that the proposal would come during the trip.

According to excerpts quoted by the Daily Mail, Nicholl wrote that "Kate's heart was heavy" when, on the couple's final day in Kenya, there was still "no sign of a proposal."

"By the time they headed to Sarara [in the heart of Kenya] for another safari with two friends from South Africa, Kate had given up hope," Nicholl wrote of Kate's mindset by the end of the trip.

Except, as it turns out, that wasn't the end of the trip after all. According to the Daily Mail, Will surprised Kate by revealing that he had secretly extended their trip and had booked them for a day and a night at the Il Ngwesi Lodge, which Nicholl describes as a "remote log cabin in the heart of the countryside near the great Lake Rutundu," which William had visited before and "knew it would be the perfect place to return with someone special."

When Will got down on one knee and popped the question, Kate was reportedly floored, both because she had already mentally given up hope of a proposal during the trip and because of the "immediately recognizable" ring she was presented.

William proposed to Kate with his late mother, Princess Diana's, iconic engagement ring, which features a 12-carat oval Ceylon blue sapphire, surrounded by 14 solitaire diamonds. According to the Daily Mail, the piece cost £28,000 when now-King Charles bought it for Diana in 1981 and is now valued at more than £300,000.

In a move that many wouldn't be confident enough to make, Will had apparently been carrying the valuable and famous ring around in his backpack for three weeks in Africa before pulling off his surprise proposal to Kate.

Kate was, understandably, rendered "speechless" by the romantic gesture, according to Nicholl—and according to Kate herself, who later described the proposal as "very romantic" and admitted it was a "total shock."

The proposal wasn't just a surprise to Kate. According to Nicholl, Will didn't tell anyone he planned to pop the question during the Kenya trip (although his brother, Prince Harry, did know that a proposal was on the horizon).

"Although no one—not even his father or brother—knew of his intention to propose to Kate while away, William had spoken with Harry to make sure his younger brother was happy for him to have their mother's ring, as and when the time came," Nicholl wrote.

Will and Kate decided to keep the proposal a secret until the prince had a chance to make sure a very specific person was the first to hear about it—and to get the news personally from him: Kate's father, Michael Middleton.

When Will and Kate got back to the U.K. from their trip, they invited Kate's parents, Michael and Carole Middleton, to meet them the following weekend at the Aberdeenshire estate of Birkhall.

"Just before supper on the first night, William took Michael into the dressing room, poured them both a large whiskey, and asked for permission to marry Kate," Nicholl wrote. "Without a moment's hesitation, Michael gave William his blessing."

Even though Michael Middleton gave his blessing, the engagement was still top secret—even from Kate's mother, Carole. That's because royal protocol dictated that the next person to hear the news had to be William's grandmother, Queen Elizabeth, who had to give her blessing in order for the engagement to become official.

The Queen did give the engagement her blessing, of course, and Will and Kate were able to publicly announce the engagement on November 16, 2010.

During their engagement interview, Kate told ITV News's Tom Bradby, that the proposal "very romantic" and, of William, "there's a true romantic in there."

"As every guy out there will know, it takes a certain amount of motivation to get yourself going," William added, sharing some details about planning the proposal. "So I was planning it, and then it just felt really right out in Africa. It was beautiful."

William's "true romantic" side was on full display when he explained his decision to propose with his late mother's engagement ring.

"It's my mother's engagement ring, and it's very special to me, as Kate is very special to me now as well. It was only right the two were put together," he said (per the Daily Mail). "It was my way of making sure Mother didn't miss out on today and the excitement and the fact that we're going to spend the rest of our lives together."