Prince William and Kate Middleton met at university in Scotland and they dated for many years after graduating in 2005. After a small separation in 2007, the pair announced their engagement in November 2010.
More than a million people thronged London's streets for the April 2011 wedding and a worldwide audience of over 2 billion watched the sumptuous show of British pageantry which breathed new life into the monarchy.
To mark the marriage, the Queen made William the Duke of Cambridge and Kate became Her Royal Highness the Duchess of Cambridge.
For their first overseas tour the royal couple visited Canada and America in July 2011. They delighted cheering Canadians by showing their sporty side and taking part in dragon boat racing, with William giving Kate a consoling hug after his boat won.
In February 2012 William arrived in the Falkland Islands for a posting as a military search-and rescue pilot, adding to resurging tensions between London and Buenos Aires.
At the beginning of June 2012 William and Kate joined the Queen, Prince Philip and other senior royals on board a gilded royal barge in a spectacular highlight of four days of nationwide events marking the monarch's Diamond Jubilee.
In driving rain and biting wind, cheering crowds celebrating the Queen's 60th anniversary on the throne watched a flotilla of 1,000 boats follow the royal barge on a 7-mile (11 kilometre) journey down the River Thames.
The royal family were out in force during the London 2012 Olympics, and William and Kate made frequent appearances both as spectators and behind the scenes, meeting some of the thousands of Team GB volunteers who contributed to the success of the games.
In September they went on a Jubilee tour of southeast Asia, representing the Queen. The relaxed couple danced with locals in Tuvalu and were presented with necklaces by topless local women in the Solomon Islands.
This was at the time a French magazine published topless pictures of Kate whilst on holiday in the south of France, sparking Prince William to instigate legal action.
In December Buckingham Palace announced William and Kate were expecting their first baby. They were forced to reveal the private information early after Kate was admitted to hospital with acute morning sickness.
Kate's growing baby bump was scrutinised the world over. One of the couple's last public engagements together was a fun-filled tour of the Harry Potter studios, where they jousted with wands.
On June 4, Prince William, Kate and Prince Harry celebrated the Queen's 60th anniversary of her coronation at a special service at Westminster Abbey.
The world's media camped outside the Lindo Wing at St Mary's hospital in central London for a couple of weeks before Kate was finally admitted on July 22 and gave birth to the couple's baby boy - who is now third in line to the British throne.
Prince George Alexander Louis was carried out by the proud parents to meet the press on July 23 and the crowd cheered wildly as Kate handed over the bundled up baby into the arms of Prince William.
The Duke and Duchess were first seen together in public after becoming parents in Anglesey, North Wales, where they used to live, on August 30. Catherine made a surprise appearance alongside her husband to start the Anglesey ultra marathon.
Two weeks later the couple attended the inaugural Tusk Conservation Awards at the Royal Society in London. This came just after Prince William announced he was to step down from the military and focus on his charity and royal duties for the immediate future.
More recently Catherine showed off her volleyball skills as she visited a SportsAid workshop in London on Friday (October 18). Kate, who is the patron of the charity, joined in with a game of volleyball, despite being dressed up in a suit jacket and wedges.
The christening of Prince George takes place on Wednesday (October 23) at the Chapel Royal inside St James's Palace. The public will see the young family arrive, but the service will be private.
It will be the first time the baby will have been since in public, since he emerged just a day old from hospital in his parents arms.