On this day exactly 12 years ago, the Prince and Princess of Wales made a huge announcement to the world - they were engaged.
The loved-up couple revealed that they were to marry with Kate showing off her gorgeous sapphire engagement ring that had once belonged to William's late mother Princess Diana.
To mark the occasion, the pair also sat down for a rare interview with ITV's Tom Bradby, where they talked about their friendship that blossomed into love, William's romantic proposal in Kenya and how their break-up in 2007 ended up being short-lived.
But when looking at the interview that was given way back in 2010, William refers to his wife-to-be by a name that he rarely uses in public now.
On nine separate times throughout the interview, he calls her 'Kate' - the name that the princess was known by during her time at university that is still used by many today.
However, since their wedding several months later in April 2011, William has hardly ever called her by the name Kate when out and about or in speeches - and has instead resorted to her full name of Catherine.
Even Kate herself introduces herself as Catherine in public, and at an engagement last week when a curious little boy asked what she was called she replied: "Catherine".
Despite their engagement being 12 years ago, their love story dates back even further as they first laid eyes on each other when they were both students at St Andrews University in Scotland.
But it seems their first encounter doesn't stick in each of their minds in the same way.
During their engagement interview, William admitted he would have to "wrack his brains" to remember their first meeting.
But Kate on the other hand remembers the moment perfectly, and it's fair to say it understandably probably wasn't her most cool and collected moment.
She said: "I actually went bright red when I met you and scuttled off feeling very shy about meeting you.
"William wasn't there for quite a bit of the time initially, he wasn't there from Fresher's 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 on."
William and Kate also spoke about their brief split and explained why it was so important to their relationship.
The now Prince of Wales said: "We did split up for a bit.
"We were both very young, it was at university and we were both finding ourselves and being different characters and stuff.
"It was very much trying to find our own way and we were growing up.
"It was just a bit of space. It worked out for the better."
However, 15 years on from that brief split, things have gone from strength to strength for the couple.
After their wedding, they welcomed three beautiful children - Prince George, Princess Charlotte and Prince Louis.
And last year, they marked 10 years of marriage with a series of gorgeous portraits taken at their London home Kensington Palace.
