When William proposed to Kate in 2010, he made the “hugely moving personal decision” to give her Diana’s engagement ring. He had been carrying it around with him for three weeks waiting for the right moment to pop the question. Eventually, he chose a secluded log cabin in the foothills of Mount Kenya, a scene which Kate described as “romantic” in their engagement interview. Related articles Royal news: The Queen told William and Kate to 'rip up' wedding plans Royal news: How William 'planned to extricate himself from Kate' William said in the same interview: “I’d been carrying it around with me in my rucksack for about three weeks before that and I literally would not let it go. “Everywhere I went I was keeping hold of it, because I knew this thing, if it disappeared, I would be in a lot of trouble. “I thought it was quite nice, because obviously she’s not going to be around to share in any of the fun and excitement of it all, so this is my way of keeping her close to it all.” Royal reporter Victoria Murphy explained this to the documentary ‘Prince William at Thirty’, uploaded to YouTube in June 2012. READ MORE: How Harry and William mae emotional revelation about Diana at wedding Prince William proposed to Kate Middleton with Princess Diana's ring (Image: GETTY) The sapphire and diamond engagement ring (Image: GETTY) She said: “It was a hugely moving personal decision and he did it because he wanted his mother to be a part of the wedding and a part of their happiness.” Royal expert Katie Nicholl added: “When he finally proposed it was with Diana’s diamond and sapphire engagement ring. “One doesn’t want to think what would happen if that rucksack somehow went missing!” William had been 15 years old when Diana was tragically killed in a car accident in Paris. Related articles The HEARTBREAKING thing Prince William did to ‘comfort’ Diana Kate Middleton could emulate Princess Diana with THIS touching gesture Both he and his 12-year-old brother Harry were devastated. However, they chose to keep her memory alive over the years, by continuing her charitable work and holding events in her honour. As Diana would never get to see either of her sons marry – William in 2011 to Kate and Harry in 2018 to Meghan Markle – this was one way of having her involved. Kate expressed how much the gesture meant to her in their first interview together, but also seemed to feel a sense of huge responsibility. Royal engagement photographs (Image: GETTY) Royal expert Victoria Murphey on documentary (Image: YouTube / RedSquirrelCrossing) She said: “I just hope I look after it! It’s very very special.” William teased: “If she loses it, she’s in big trouble.” The ring consisted of a 12-carat oval blue sapphire, cut into facets and surrounded by 14 solitaire diamonds, while the setting is made from 18K white gold. Originally, Harry had possession of the engagement ring after Charles allowed the boys to each select momentos, but they swapped when William decided to propose to Kate. Diana and Charles married in 1981, Kate and William married in 2011 (Image: GETTY) The ring was also resized to fit Kate, as the original was slightly too big for her, which they did by placing small platinum beads inside the ring’s band. In that very first interview, Kate wore a sapphire-blue silk jersey dress to match the beautiful ring. The couple went on to marry in a spectacular service at Westminster Abbey in 2011. They are now the proud parents of Prince George, Princess Charlotte and Prince Louis.All rights reserved for this news site express.co.uk and under his responsibility