LONDON - Prince William and his wife, Kate, are expecting their first child. Here's some key moments in their romance.

— September 2001: William enrolls at St. Andrews University in Scotland, where he meets Kate — a fellow art history student.

— March 2002: Kate models a transparent dress over black lingerie at a charity fashion show at St. Andrews. It's widely reported that William paid for a front-row seat at the show.

— September 2002: William and Kate move into a shared student house with two other friends.

— May 2003: The couple are pictured deep in conversation at a rugby match, sparking rumours of a romance.

— March 2004: William and Kate's romance becomes public when they are pictured together on a Swiss skiing holiday. Later that year, media reports that they split briefly as William complained of feeling claustrophobic.

— April 2005: Kate does not attend the wedding of William's father, the Prince of Wales, and Camilla Parker Bowles in Windsor. Later that year, the pair graduate in the same ceremony at St. Andrews.

— December 2006: William is commissioned as an army officer in front of the queen at Sandhurst and joins the Household Cavalry as a second lieutenant. Kate attends the ceremony.

— April 2007: British newspapers report that William and Kate have split up. Prince Charles' Clarence House office refuses to comment, but does not deny the report.

— July 2007: Media in the U.K. report that William and Kate have rekindled their romance.

— April 11, 2008: Kate is seen at William's side at his graduation ceremony from the Royal Air Force, taken as a signal by royal watchers that their relationship is now serious.

— October 2010: William proposes to Kate while on a private holiday in Kenya.

— November 2010: Clarence House officially announces the engagement.

— December 2010: Kate and William attend a charity event to raise money for cancer research, Kate's first official event as a royal fiancee.

— April 29, 2011: Prince William and Kate Middleton marry in a lavish ceremony at London's Westminster Abbey. In the months that follow, they travel the globe, often making appearances in honour of Queen Elizabeth II's Diamond Jubilee.

— Sept. 14, 2012: A French magazine publishes photos of Kate sunbathing topless at a private house in southern France, prompting a strong condemnation from the royal family.

— Dec. 3, 2012: Royal officials announce that Kate is pregnant with her first child, yet hospitalized for morning sickness.

Take a look at the Royal couple's last public appearance -- in their namesake town of Cambridge -- before announcing the big baby news.

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• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Emma Henson, 7, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  A gust of wind catches the hair of The Duchess of Cambridge as she arrives at Peterborough City Hospital in Cambridgeshire, during an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets well wishers during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Dorothy West, 96, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Sumi Willett during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duke and Duchess of Cambridge pose for a picture taken by patient Linda Smith, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duke and Duchess of Cambridge pose for a picture taken by patient Linda Smith, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets well wishers during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Sumi Willett during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Emma Henson, 7, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Sumi Willett during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  Sumi Willett who met with the Duchess of Cambridge, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Emma Henson, 7, during a visit to Peterborough City Hospital in Cambridgeshire, as part of an official visit to Cambridge.

• The Duke And Duchess Of Cambridge Make An Official Visit To Cambridge

  CAMBRIDGE, CAMBRIDGESHIRE - NOVEMBER 28: Catherine, Duchess of Cambridge meets children working on projects as she visits Manor School as she pays an official visit to Cambridge with Prince William, Duke of Cambridge on November 28, 2012 in Cambridge, Cambridgeshire. (Photo by Chris Jackson - WPA Pool/Getty Images)

• The Duke And Duchess Of Cambridge Make An Official Visit To Cambridge

  CAMBRIDGE, CAMBRIDGESHIRE - NOVEMBER 28: Prince William, Duke of Cambridge meets pupils as he visits Manor School as she pays an official visit to Cambridge with Prince William, Duke of Cambridge on November 28, 2012 in Cambridge, Cambridgeshire. (Photo by Chris Jackson - WPA Pool/Getty Images)

• The Duke And Duchess Of Cambridge Make An Official Visit To Cambridge

  CAMBRIDGE, CAMBRIDGESHIRE - NOVEMBER 28: Prince William, Duke of Cambridge meets pupils as he visits Manor School as she pays an official visit to Cambridge with Prince William, Duke of Cambridge on November 28, 2012 in Cambridge, Cambridgeshire. (Photo by Chris Jackson - WPA Pool/Getty Images)

• The Duke And Duchess Of Cambridge Make An Official Visit To Cambridge

  CAMBRIDGE, CAMBRIDGESHIRE - NOVEMBER 28: Catherine, Duchess of Cambridge and Prince William, Dukem of Cambridge watch a performace as they visit Manor School as she pays an official visit to Cambridge with Prince William, Duke of Cambridge on November 28, 2012 in Cambridge, Cambridgeshire. (Photo by Chris Jackson - WPA Pool/Getty Images)

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge on a tour of Jimmy's resettlement centre in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge on a tour of Jimmy's resettlement centre in Cambridge.

• Royal visit to Cambridgeshire

  The Duke and Duchess of Cambridge on a tour of Jimmy's resettlement centre in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge on a tour of Jimmy's resettlement centre in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge on the balcony of the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duke of Cambridge meets Oliver Duell, 7, at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duke of Cambridge greets well wishers during a walkabout in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Clive Marshall, 51, at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duke and Duchess of Cambridge arrive at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duke of Cambridge greets well wishers during a walkabout in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets James William Davies, 5 months, who was named after Prince William, with mother Tessa Davies during a walkabout in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets James William Davies, 5 months, who was named after Prince William, with mother Tessa Davies during a walkabout in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge meets Oliver Duell, 7, at the Guildhall in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge speaks to University staff and students during a visit to Senate House in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge speaks to University staff and students during a visit to Senate House in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge speaks to University staff and students during a visit to Senate House in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge arrives at Senate House, University of Cambridge, as the Royal couple mark their first official joint visit to Cambridgeshire as The Duke and Duchess of Cambridge.

• Royal visit to Cambridgeshire

  Young girls watch from a university window as they await the arrival of the Duchess of Cambridge at Senate House, University of Cambridge, as the Royal couple mark their first official joint visit to Cambridgeshire as The Duke and Duchess of Cambridge.

• BRITAIN - ROYALS - CAMBRIDGE

  Catherine, the Duchess of Cambridge meets members of the public during a walk through the streets central Cambridge ahead of an event at the Senate House on November 28, 2012. Britain's Prince William and his wife Catherine visited the university city that is home to their dukedom for the first time since they were given their official titles. William and Catherine, who were given the titles the Duke and Duchess of Cambridge when they married last year, received an ecstatic welcome from hundreds of people who started lining the streets in the early hours of the morning. AFP PHOTO/Leon Neal (Photo credit should read LEON NEAL/AFP/Getty Images)

• BRITAIN-ROYALS

  Catherine, The Duchess of Cambridge looks on during a visit to Senate House in Cambridge on November 28, 2012. Britain's Prince William and his wife Catherine visited the university city that is home to their dukedom for the first time since they were given their official titles.William and Catherine, who were given the titles the Duke and Duchess of Cambridge when they married last year, received an ecstatic welcome from hundreds of people who started lining the streets in the early hours of the morning. AFP PHOTO/POOL/Kirsty Wigglesworth (Photo credit should read KIRSTY WIGGLESWORTH/AFP/Getty Images)

• Royal visit to Cambridgeshire

  The Duchess of Cambridge speaks to University staff and students during a visit to Senate House in Cambridge.

• Royal visit to Cambridgeshire

  The Duchess of Cambridge speaks to University staff and students during a visit to Senate House in Cambridge.

• Royal visit to Cambridgeshire

  The Duke and Duchess of Cambridge arrive at Cambridge station.

• The Duke And Duchess Of Cambridge Make An Official Visit To Cambridge

  CAMBRIDGE, UNITED KINGDOM - NOVEMBER 28: Catherine, Duchess of Cambridge meets dignitaries as she arrives at Cambridge Guildhall as she pays an official visit to Cambridge with Prince William, Duke of Cambridge on November 28, 2012 in Cambridge, England. (Photo by Chris Jackson/Getty Images)

• The Duke And Duchess Of Cambridge Make An Official Visit To Cambridge

  CAMBRIDGE, UNITED KINGDOM - NOVEMBER 28: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge smile and wave to the crowds from the balcony of Cambridge Guildhall as they pay an official visit to Cambridge on November 28, 2012 in Cambridge, England. (Photo by Chris Jackson/Getty Images)