Profile: Kate, Duchess of Cambridge
The Duchess of Cambridge - who is now expecting a baby - has moved from a comparatively ordinary existence to a prominent role in the Royal Family since she started going out with Prince William in 2001.
The couple met while Catherine Middleton was studying art history at St Andrews University, in Fife - where they shared accommodation for four years.
Their wedding at Westminster Abbey in April 2011 was watched on television by millions of people around the world.Popular and talented
The duchess was born on 9 January 1982.
She grew up in Bucklebury, in Berkshire, where her parents, Michael and Carole Middleton, run a mail-order business selling toys and games for children's parties from a converted barn close to their home.
The eldest of three children, she was educated at the exclusive Marlborough College in Wiltshire, where she was described as level-headed, popular and talented, and captained the school hockey team.
Her sister, Pippa, 29, is a party planner who was voted No 1 in Tatler magazine's 2008 poll of the "200 coolest kids in town".
Her brother, James, 25, has launched a baking company.
After they met at St Andrews, Catherine and William's relationship apparently flourished during weekends alone on the Queen's Balmoral estate.
For a while, at least, they were guaranteed some privacy, following an agreement worked out between the palace and press while he was a student.
But the media silence did not last, and Catherine was first brought to the public's attention after several tabloids pictured her beside Prince William and Prince Charles at the Swiss ski resort of Klosters in 2005.
The photographs appeared despite efforts by aides to keep the holiday private.
Newspaper interest grew when Catherine graduated and moved to London.
In October 2005, after the publication of a photo which showed her looking out of a window on a London bus, her lawyers wrote to newspaper and magazine editors asking them to respect her privacy.
They claimed photographers had followed Catherine almost every day and night since she left university.
Speculation over an engagement was sparked in February 2006, when it was suggested she would receive her own royal security.
In December 2006, Catherine was again in the headlines after she and her mother attended a ceremony at Sandhurst Royal Military Academy, to watch Prince William being commissioned as an army officer.
The occasion was notable as the first time she had been seen at a high-profile public event attended by the Queen and other senior royals.Media scrum
Rumours of an engagement reached a peak around the time of Catherine's 25th birthday in January 2007, when the media scrum took up residence outside her Chelsea home.
The paparazzi free-for-all drew inevitable comparisons with the prince's late mother, killed in a car crash in Paris whilst being pursued by photographers.
Prince William and Prince Charles appealed for her to be left alone, and some newspapers agreed to stop using paparazzi shots of her.
In March, Catherine's lawyers made an official complaint to the Press Complaints Commission over a photo published in the Daily Mirror.
It showed her clutching a takeaway coffee cup and car keys as she headed to work. The Mirror issued a public apology and the complaint was withdrawn.
Media pressure appeared to take its toll and was blamed when the couple split in April 2007, although no official statement was issued by either.
Reports of a reconciliation were denied in June 2007, with the couple insisting they were "just good friends" after being spotted together at the Concert for Diana at Wembley.
They were then seen in public on a number of occasions.
Catherine was present when the prince received his RAF wings from his father at RAF Cranwell in April 2008 and in Windsor when he became a Knight of the Garter in June.
The couple announced their engagement in November 2010, and at the time Catherine said joining the Royal Family was a "daunting prospect".
"Hopefully I'll take it in my stride," she added.
Since her marriage the Duchess became the patron of four charities: Action on Addiction, East Anglia's Children's Hospices, the Art Room and the National Portrait Gallery.
She and Prince William have undertaken two official overseas tours - to North America and Canada in 2011, and to South East Asia in 2012 to mark the Queen's Diamond Jubilee.
In September this year, the royals took legal action against a French magazine that published topless pictures of the duchess, taken during their private holiday.
On December 3, St James's Palace announced that the Duchess of Cambridge is expecting a baby, and that Catherine had been admitted to hospital with acute morning sickness.