John Stillwell - WPA/Getty Images

As well he should've been, considering how close their fairy tale came to fracturing.

Those days may feel like ancient history, now that they've been married for 15 years and are parents of Prince George, 12, Princess Charlotte, 10, and Prince Louis, 8. They've also weathered all sorts of family turmoil together, including Kate's cancer diagnosis in 2024, a year William called "the hardest" he'd ever had.

"You know, life is sent to test us as well," he said on Eugene Levy's Apple TV+ show The Reluctant Traveler, "and being able to overcome that is what makes us who we are."

Chris Jackson/Getty Images

"I like to keep my private life private," William said in a rare Q&A session with the media for his 18th birthday in June 2000.

Asked how he managed to have a private life amid all the attention he received, he replied, "In my own way. Trying to explain might be counterproductive."

Though Kate was certainly aware of William's existence long before they crossed paths—and The Crown played up the idea that her mother was angling for them to meet—they eventually made each other's acquaintance in the dorm during their first year at St Andrews.

They became fast friends, bonding over sports and art. They went for morning swims and took strolls through town, and Kate was an obliging ear when William struggled with art history and decided to switch his concentration to geography.

But they remained just mates, and William started dating Carly Massy-Birch, a creative writing student he met in drama club.

Then, at the aforementioned fashion show in March 2002, William started seeing Kate as more than just a friend.

"It was clear to us that William was smitten with Kate," a friend recalled in royal biographer Katie Nicholl's 2011 book The Making of a Royal Romance. "He actually told her that she was a knockout that night, which caused her to blush."

Francine Orr - Pool/Getty Images

When Kate and William began year three at St Andrews in September 2003, they were less cautious about keeping their relationship under wraps. They lessened their roommate count to one (not including security), moving into a four-bedroom cottage on the grounds of Balgrove House with their friend Oliver "Oli" Baker—who is still a close mate and one of Prince George's godparents.

The cat was then forever let out of the bag in the spring of 2004 when Will was photographed with his arm around Kate atop a mountain in the Swiss village of Klosters, a favorite royal family skiing spot, and The Sun was all too happy to share the news that William had a girlfriend.

The press was all over Kate after that. She comported herself as admirably as possible and her family's home in Bucklebury became a cozy weekend refuge for her and William.

But William then planned a sailing trip to the Greek islands with his mate (and Louis' future godfather) Guy Pelly that did not include Kate for the summer of 2004.

Aaron Chown - Pool/Getty Images

Yet, as they graduated on June 23, 2005, Kate wasn't convinced that William was really in it for the long haul.

"I'm only 22 for God's sake," William told a reporter in April 2005, a few days before his father wed now-Queen Camilla, having been asked if marriage was on his mind as well. "I'm too young to marry at my age. I don't want to get married till I'm at least 28, or maybe 30."

But that summer they traveled to Kenya, where they stayed in a $1,500-a-night cottage at the Masai Lodge in Nairobi.

Kate joined the royal family for their annual Boxing Day shoot at Sandringham, where she and William also rang in 2006. Then it was off to a private ski holiday in Klosters, minus the photographers who snapped away at the couple—and this time caught them kissing.

And so commenced royal engagement watch.

While William got ready to attend Royal Military Academy at Sandhurst, where he trained to be a helicopter pilot, Kate moved into a flat in London and got a job as an accessories buyer for British fashion retailer Jigsaw.

They spent spring break of 2006 in Mustique—"Prince William, Bikini-Clad Girlfriend Caused a Stir," read an ABC News headline—and that December Kate and her parents had front-row seats at her boyfriend's passing out ceremony (which isn't what it sounds like) at Sandhurst. Like William's granny, Queen Elizabeth II, Kate wore a red coat.

The couple seemed to be in the engagement home stretch. Charles' Clarence House press team began looking after Kate, too, and William's security was tasked with her protection whenever they were together.

In December 2006, Kate was invited to Christmas lunch at Sandringham—which was quite the upgraded invitation for a significant other.

But then William canceled plans to spend New Year's with Kate's family in Scotland. He then left for his first posting, with the Blues and Royals of the British Army's Household Cavalry, in Dorset on Jan. 8, 2007—the day before Kate's 25th birthday.

It was right around that time that a piece in The Spectator heralded Kate as "THE NEXT PEOPLE'S PRINCESS," after which the paparazzi followed her everywhere.

"Miss Middleton should, like any other private individual, be able to go about her everyday business without this kind of intrusion," the palace said in a terse statement. "The situation is proving unbearable for all those concerned."

Deciding that four years had been enough of a courtship, the papers were predicting that an engagement was forthcoming.

Instead, sometime between March 31, 2007, when they went on a double date with pals Hugh and Rose van Cutsem, and April 3, when Kate left for a trip to Ireland, William broke up with her.

"In an emotionally charged 30-minute conversation, they both acknowledged they were on 'different pages,'" Robert Jobson wrote in his 2024 biography Catherine, The Princess of Wales. "It was a devastating blow to Catherine, who felt doubly let down at being dumped over the phone."

But just as she didn't let William think he could swoop in out of nowhere and make out with her after the student fashion show in 2002, she wasn't going to let him (or, by then, all of Britain) think she was pining away for the prince.

Kate started training for a charity rowing challenge with an all-girl crew. "Kate had always put William first," Emma Sayle, the group's leader, recalled in Marcia Moody's 2018 book Kate: A Biography, "and she said this was a chance to do something for herself."

Pippa Middleton moved in with her big sister in London and they maintained a packed social schedule. Needless to say, Kate was never photographed looking any less than her best and ended up on the cover of Hello!.

She was also spotted being escorted home from a party one night by Willem Marx, an old boyfriend from Marlborough.

Chris Jackson - Pool via Samir Hussein/WireImage