More than a decade after their fairytale wedding, the Prince and Princess of Wales are stronger than ever. The couple have weathered many storms – from Kate’s cancer diagnosis to Prince Harry’s swipes at the royals – but it has only served to unite them further.

There was, however, a time that William had to keep a secret from his wife – and it was life-changing. William and Kate were together for ten years before the Prince decided to pop the question. The happy couple announced their engagement in November 2010, and in an interview with ITV’s Tom Bradby, shared details of the romantic Kenyan holiday during which William proposed with his late mother Princess Diana‘s sapphire engagement ring.

The Prince explained at the time: “It is the place my father took my brother and me shortly after our mother died. And when deciding where best to propose to Catherine, I could think of no more fitting place than Kenya to get down on one knee.”

William then revealed that he had secretly been carrying the iconic ring, made by royal jeweller Garrard, in a backpack for a whole three weeks – without Kate finding out. He joked: “I knew if this thing disappeared, I’d be in a lot of trouble”.

William and Kate‘s love story started when they met as students at St Andrews university . They initially started out as friends – they were on the same history of art course, lived only a few doors from each other in an accommodation block, and shared a love of sport and fitness. And their relationship might have remained platonic until fate intervened. Kate signed up to take part in a charity fashion show at the university, and it made William see her in a completely different light.

The royal had paid £200 for a front-row seat at the show in spring 2002 and, when Kate took to the runway in a transparent dress , is said to have turned to his friend and whispered: “Wow, Kate’s hot!” Ingrid Seward, editor in chief of Majesty magazine, previously revealed: “Kate and William’s relationship began as a friendship, but when Kate did that catwalk show, that was the first time he really looked at her as more than a lovely friend. Early dates were very simple.

“They used to go to a place called Ma Bells and they would be very discreet. Often William would turn up and Kate would appear later but they wouldn’t be together. William wanted to keep it under wraps as long as he could . They shared an apartment together in their second year and that’s where their relationship moved up a pace.”

William and Kate also spoke about the start of their relationship when they sat down for the engagement interview in November 2010. Tom Bradby asked the pair: “When did you first set eyes on each other and what did you think?”

William replied: “It’s a long time ago now, Tom, I’m trying to wrack my brain. We obviously met at university – at St Andrews we were friends for over a year first and it just sort of blossomed from then on. We just spent more time with each other, had a good giggle, had lots of fun and realised we shared the same interests and had a really good time.

“She’s got a really naughty sense of humour, which kind of helps me because I’ve got a really dry sense of humour, so it was good fun, we had a really good laugh and things happened.”

Tom then asked Kate, “What did you think of William? It’s clearly not quite the same as meeting your average university student , or maybe it was, what was your first impression?”

The future Princess very sweetly confessed: “Well I actually think I went bright red when I met you and sort of scuttled off, feeling very shy about meeting you. Actually William wasn’t there for quite a bit of the time initially, he wasn’t there for Freshers Week , so it did take a bit of time for us to get to know each other but we did become very close friends from quite early.”