We look back at William and Catherine's fairytale relationship in pictures...
The Duke and Duchess of Cambridge - they've been winning hearts all over the world ever since they got together way back in 2003, after meeting at the University of St. Andrews.
And the nation has followed their love story with glee, from their engagement in 2010, to their huge wedding in 2011, all the way through to the birth of Prince George in 2013 and Princess Charlotte in 2015.
See a collection of photos of their best ever moments here...
Most recently, Catherine and William, joined by Prince Harry, headed down to the 2017 London Marathon, to support runners taking part in the race for their mental health campaign, Heads Together. The Duke and Duchess and Harry pressed the starting buzzer for the race, cheered on participants, and handed out water to people around the course.
On their first 2017 tour as a couple...
On their most recent royal tour as a couple, Catherine and William are pictured with the Eiffel Tower in the distance whilst in Paris.
At the 2017 BAFTAs
The couple attended the 2017 BAFTAs together in March, with Catherine donning a gorgeous off-the-shoulder Alexander McQueen dress.
The Cambridges at Christmas, December 2016
The Duke and Duchess, along with their two children George and Charlotte, made their way to the St Mary Magdalene Church in Englefield on Christmas Day last year for a special celebration. The adorable family joined many members of the royal family, and even the rest of Catherine's family, the Middletons. Her sister Pippa, brother James, and parents Michael and Carole were in tow, along with Pippa's fiancé, James Matthews.
William's cheeky joke about Catherine's cooking, 2016
The Duke and Duchess of Cambridge recently spent a glamorous evening without Prince George and Princess Charlotte at a charity gala dinner - but we have a feeling that William may have 'put his foot in it' with his wife! During the event the couple expressed their excitement about the meal, prepared by five Michelin-starred chefs. Catherine told them: "William has to put up with my cooking most of the time", to which to Duke added, "It's the reason I'm so skinny!" Thankfully, Catherine seemed to take his cheeky joke well, and the couple appeared to enjoy their evening as guests of honour at the event.
Traditional at the Order of the Garter service, 2016
Following a weekend of celebrations for the Queen's 90th birthday, the Duke and Duchess of Cambridge joined Queen Elizabeth at the traditional Garter Day service. Catherine chose a vibrant red coat by Catherine Walker for the service, while Prince William wore a traditional cape to reflect the history of the event.
A portrait of Catherine and William revealed for 5th anniversary
To celebrate their fifth wedding anniversary, a new portrait of the Duke and Duchess of Cambridge was released along with a Thank You card, which the couple sent to everyone who congratulated them. The photograph, possibly taken in the gardens at Kensington Palace, was shot by Christ Jelf, who snapped the couple and their children for the family Christmas card. Royal photographer Paul Ratcliffe shared a picture of the card and the message inside via Twitter. 'The Duke and Duchess of Cambridge were so touched that you took the trouble to write as you did on the occasion of their 5th Wedding Anniversary. It really was most thoughtful of you and Their Royal Highnesses send you their warmest thanks and best wishes,' the card read.
Launch of the Heads Together campaign, 2016
The Duke and Duchess of Camrbridge are well-known for their support of mental health charities, and have spent much of their time campaigning for more support for young people and adults with mental health issues, so their most recent campaign is the perfect fit. Prince William, Catherine and Prince Harry worked together to support the Heads Together mental health charity campaign, which was the 2017 Virgin Money London Marathon Charity of the Year. The campaign hoped to change the national conversation on mental wellbeing, and is working in partnership with various charities including Place 2 Be, of which the Duchess is patron. The project was the biggest that the royal trio have undertaken together.
On their first royal tour as family, 2016
The Cambridges on their first royal tour as a family. Catherine and William returned to Canada with Prince George and Princess Charlotte in tow this time - and it sure made for some adorable photographs.
Little Prince George meets the President, in 2015
The Duke and Duchess of Cambridge were the perfect proud parents as their son Prince George met Barack Obama for the first time in 2015. Prince George greeted the US President in a dressing gown and slippers after being allowed to stay up a little after his bed time for the meeting. The two parents looked on proudly as he played on his rocking horse, which was a gift from President Obama when he was born. What an adorable family moment!
The Duke and Duchess follow in the footsteps of Princess Diana, 2015
The Duke and Duchess' trip to India hit headlines between April 11th and 16th, with their sporting activities, official engagements and colourful welcome ceremonies documented scrupulously for the whole world to see (and envy!). The highlights of the trip can be viewed here. On the final leg of their trip, Catherine and William visited the Taj Mahal, marking 24 years since Princess Diana visited the 17th century monument. The Duke and Duchess' communications secretary said: "The Duke of Cambridge is of course aware of the huge esteem his mother, the late Princess of Wales, is held in in India and he appreciates the status of the images that exist of the Princess at the Taj. "He feels incredibly lucky to visit a place where his mother's memory is kept alive by so many there...The Duke and Duchess are looking forward toseeing this beautiful?place for themselves and creating new memories as they say thank you to?the people of India at the conclusion of this tour."
Keen archers on tour in Bhutan, 2015
The Cambridge's Kennedy moment on a royal tour of Bhutan, 2015
The family's first holiday as a foursome, 2015
Official photographs were released of the Cambridges enjoying their first family holiday together in the French Alps in 2015.
Princess Charlotte's first holiday, 2015
The Duke and Duchess still looking very much in love, 2015
Catherine and William are known for their competitive streaks, and we've no doubt that the pair, who share a mutual love of skiing, have managed to fit in a few races!
Happy birthday Catherine!
Princess Charlotte's christening, 2015
The Duke and Duchess greeted crowds of well wishers at the church of St.Mary Magdalene on the Sandringham Estate after the christening of their daughter Charlotte, on 5th July 2015. The adorable princess was christened about a month after her birth.
At the hospital after the birth of Princess Charlotte, 2015
As is royal tradition, the couple stepped out to introduce the world to their second child, Princess Charlotte, on 2nd May 2015. The royals were met with crowds of photographers, and waved excitedly to the awaiting group. This is the very first photo of Princess Charlotte, with her doting parents.
Enjoying their outdoor passions together in 2015
The Duke and Duchess of Cambridge enjoyed an adventurous day out at the Towers Residential Outdoor Education Centre in Wales in 2015, which supports children with mental health issues. Showing off their famously sporty side, Kate donned a helmet and boots to have a go at abseiling, and was later joined by her husband William.
Celebrating St. Patrick's Day, 2015
The couple are seen here at the St. Patrick's Day Parade, in one of Catherine's last public appearances before her maternity leave with Princess Charlotte started. Catherine accompanied her husband in his role as royal colonel of the Irish Guards.
Attending The Spectre Premiere, 2014
The pair dazzled as they stepped out in London for the Spectre premiere in 2014. The couple have become somewhat of a regular on red carpets, stepping out for multiple big premieres in London. The Duchess opted for a bespoke pastel blue gown by Jenny Packham - one of her favourite designers - while William wore a smart, black tie suit.
At The BAFTA Game Design competition, 2014
The couple shared a giggle at the BAFTA Game Design Competition - their first official visit to Dundee as a couple. Catherine looks up adoringly at William in this photo.
With a vintage plane at Blenheim, 2014
Catherine joined in with William's passion for planes at Omaka Aviation Heritage Centre in New Zealand in the winter of 2014. The pair shared a joke as the Duchess peered into the tiny plane, while William set confidently in the cockpit. William famously served as a flight lieutenant in the Royal Air Force, in 2009, and has flown helicopters for the ambulance service since then.
Greeting the Chinese president, 2014
The Duke and Duchess of Cambridge greeted the Chinese president and his wife on their state visit to the U.K. at Lancaster House in London. Catherine opted for a plum hued lace number as William politely held up an umbrella to sheild the pair (and Catherine's dress!) from the rain.
At the Rugby World Cup, 2014
The couple looked at each other adoringly as they attended the Rugby World Cup opening day to watch England play Fiji. The couple most recently attended the Wales vs. France Six Nations Rugby game, in March 2017.
At Christmas in Sandringham, 2015
Christmas has taken on a slightly different form for Catherine since she married William. The couple now usually spend the morning at a church service led by the Queen before lunch on the Sandringham estate. However, in 2015, the couple broke with tradition and spent the afternoon with the Duchess's family in Norfolk. They're pictured here arriving hand in hand at the chapel. The public display of affection is a rare one for the couple - who prefer to stay professional when out and about.
In New York, 2014
A 3-day tour of New York was a highlight for the Cambridges late in 2014. As ever, they charmed everyone they met, including hip-hop royalty Jay-Z and Beyonce and US Vogue Editor Anna Wintour who attended a gala dinner in the couple's honour on their final night in the Big Apple. There was a moment for Catherine and William to stop and reflect though as they visited the 9/11 Memorial Museum - pictured here.
With Prince George on his first birthday, in 2014
What a cutie! To celebrate their little boy's first birthday, The Duchess of Cambridge and Prince William released a set of stunning photos taken at the Natural History Museum that gave us a sneak peek in to family life. George is apparently a huge fan of dinosaurs, with Catherine revealing his favourite is the T-Rex.
Catherine, William and George for Mother's Day, 2014
Mothering Sunday took on a different meaning for the Duchess of Cambridge in 2013 - and she celebrated the day by releasing a rather special photograph of her family. William and Catherine posed with a bonny Prince George and their springer spaniel Lupo for this intimate portrait. Framed by one of the windows to their home at Apartment 1A of Kensington Palace, the royal unit looked relaxed and happy as they smiled in the early spring sunshine.
Catherine, William and George at his Christening, 2013
Another special moment for the couple. The Duke and Duchess of Cambridge welcomed guests outside St James's Palace in London to the christening of Prince George in October 2013. George wore the very same christening gown that William had been baptised in himself 35 years earlier.
Catherine, William and Prince George outside St Mary's Hospital, 2013
Britain let out a universal 'aww' in July 2013 as Catherine and William proudly showed off their new son, who was later named George Alexander Louis. George is the first child of the Duke and Duchess, and will eventually succeed his father to become the King of England.
Sharing a cuddle at the London Olympics, 2012
The couple embrace here whilst celebrating the a team GB cyclist bagging a gold medal and beating a world record, at the 2012 London Olympics.
In Kuala Lumper, 2012
Kuala Lumper was next on the the Cambridges travel itinerary in 2012. They spent their first day visiting a local mosque before attending a formal welcome lunch. Catherine put her £300 a day hairdresser to good use, debuting an elegant chignon updo to stave off the heat as she waved to waiting crowds.
At another London premiere, 2012
Red carpet premieres are all in a days work for Catherine and William! Here they are at the War Horse premiere in London in 2012.
Pregnancy rumours begin to swirl in 2011
In London, 2011
Wowing the world with their style again at the Reception in aid of the National Memorial Arboretum Appeal, St James's Palace, London, November 2011.
At Zara Phillips' wedding, 2011
Supporting the other royal wedding of the year: The wedding of Zara Phillips and Mike Tindall, in Scotland, July 2011.
On the red carpet, 2011
Looking gorgeous at the BAFTA 'Brits To Watch' event, LA, July 2011. This is the royals first appearance on a star-studded red carpet, and they've continued to put in an appearance on red carpets for major movies and theatre productions since then.
Sharing a kiss in LA, 2011
At Santa Barbara Polo Club, California, where the prince's team won, July 2011. The couple are rarely seen in such an intimate display of affection, so this is a particularly special photo of the pair.
In Canada, 2011
Getting into the spirit of things at the Calgary Stampede, Canada, July 2011. Catherine made a point to wear Canadian designers whilst on their tour of the country, and the couple certainly got into the spirit of things if these outfits are anything to go by!
On their first royal tour, 2011
Catherine and William embarked on their first official Royal Tour, in June 2011 to Canada. Here, the couple arrive in the country to excited crowds.
Attending Wimbledon, 2011
The royal couple relaxing at Wimbledon, June 2011. Catherine is a regular Wimbledon attendee, and has since been spotted at the annual summer event many times.
At the Trooping the Colour, 2011
At the Trooping the Colour, Horse Guards Parade, London, 11 Jun 2011. The celebration for the Queen's birthday was one of the first official royal events the pair attended as a married couple.
Their first official appearance as a married couple, London, 2011
Wowing in Jenny Packham at the 10th Anniversary Gala Dinner in Kensington Palace in June 2011, Catherine looked gorgeous for the couple's first official appearance since their April wedding.
Relaxing with the family in Surrey, 2011
Kate gets to know the extended family when Prince William, Prince Harry and Prince Edward gather to watch the races at The Derby, in Surrey, Jun 2011.
Meeting the Obama's at Buckingham Palace, 2011
Fresh from their honeymoon in the Seychelles, the newly appointed Duke and Duchess of Cambridge flew back to the palace to greet US President Barack Obama and First Lady Michelle Obama on their first state visit, in May 2011.
Their second married kiss...
The Duke and Duchess share their second kiss as a married couple (the first was during the ceremony), on the balcony of Buckingham Palace, to an adoring crowd below.
At their wedding in April 2011
One of the biggest moments of the couples relationship came on 11th April 2011, when they got married after seven years together, at Westminster Abbey in London. The wedding was broadcast live on TV, and drew crowds from far and wide, all desparate to catch a glimpse of the newlywed couple. After the ceremony, the couple appeared on the balcony of Buckingham Palace with their families in tow, for their first public kiss.
Announcing their engagement, 2010
Kate Middleton and Prince William announcing their engagement at St James's Palace on 16th November 2010. The couple got engaged in October 2010, whilst on holiday in Kenya. William admitted that he had nervously carried around the ring for three weeks before proposing. The Prince also used his mother, Princess Diana's, former engagement ring, which Catherine declared was "very special".
Hiding a secret in Gloucestershire, 2010
At the wedding of Harry Meade to Rosemarie Bradford at St.Peter and St.Pauls church at Northleach, Gloucestershire, in October 2010. Little did everyone know that the couple were hiding an exciting secret during the wedding - that Prince William had proposed to Catherine whilst they were on holiday.
At a rugby game, Twickenham, 2007
At the England V Italy rugby union match at Twickenham in February 2007
At the races in Gloucestershire, 2007
At The Cheltenham Festival at the Cheltenham Racecourse, Gloucestershire, in March 2007. Reportedly, the couple split just a month after this photo was taken. However, the separation didn't last long, and they were seen back together before long.
At William's graduation ceremony, Lincolshire, 2006
At the RAF Wings Graduation Ceremony, in Lincolnshire April 2008. This was an important moment for the couple, as it was the first time Catherine attended a public ceremony with senior members of the royal family, including the Queen.
At a wedding in London, 2009
With friends at The Wedding of Captain Nicholas Van Cutsem and Alice Hadden-Paton at The Guards Chapel, London, August 2009
Sharing a kiss at Eton, 2006
At the Eton College Old Boys Field Game in March 2006. Catherine was being spotted on more and more regular occassions with the royal family, prompting the public to believe that their relationship becoming more serious than ever...
Catherine and William in Switzerland, 2004
The first ever photo of the pair spotted together. The couple were in seen skiing together in Kloisters, Switzerland, publically confirming their adorable relationship.
Their younger days...
The couple began their now world-famous love story at the University of St.Andrews, all the way back in 2002. The pair famously shared a house with some other friends whilst at university, and - while they broke up for a few months whilst they - they finished together, with Catherine (then Kate) attending William's graduation.