Timeline: William & Kate's romance

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

Photo: Prince William poses for a photo on Sept. 21, 2001.

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March 2002: Middleton models a transparent dress over clearly visible 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.

Photo: A see-through dress worn by Kate Middleton during a charity fashion show at St. Andrews Universty in 200, is pictured in central London, on March 16, 2011.

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

Photo: Britain's Prince William, center, with his girlfriend Kate Middleton and brother Prince Harry, watch the England-against-Italy Six Nations rugby match at Twickenham stadium in London, Feb. 10, 2007.

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

Photo: Britain's Prince William, left, and girlfriend Kate Middleton watch the England against Italy Six Nation rugby match at Twickenham stadium in London on Feb. 10, 2007.

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June 2003: Middleton is a guest at William's 21st birthday party at Windsor Castle; in an interview he denies he has a steady girlfriend.

Photo: Prince William of Great Britain blows out the candles on his birthday cake on June 19, 2003.

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

Photo: Prince William of Wales and girlfriend Kate Middleton leave the night club Boujis on Jan. 5, 2007, in London.

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April 2005: Middleton does not attend the wedding of William's father, the Prince of Wales, and Camilla Parker Bowles in Windsor, England.

Photo: Britain's Prince Charles and his bride, Camilla, Duchess of Cornwall, leave St. George's Chapel in Windsor following the church blessing of their civil wedding ceremony, April 9, 2005.

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June 2005: William and Middleton graduate in the same ceremony at St. Andrews.

Photo: Prince William and Kate Middleton pose together following their graduation from St. Andrews University, Scotland, on June 23, 2005.

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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. Middleton attends the ceremony.

Photo: Kate Middleton sits in the stands as her boyfriend, Britain's Prince William, takes part in the Sovereign's Parade at The Royal Military Academy in Camberley, England, Dec. 15, 2006.

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

Photo: Kate Middleton is photographed on Jan. 8, 2007.

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July 2007: Media in the U.K. report that the two have rekindled their romance.

Photo: Prince William and Kate Middleton, photographed exiting a London nightclub.

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April 11, 2008: Middleton 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.

Photo: Britain's Prince William and girlfriend Kate Middleton are photographed at RAF Cranwell, England, on April 11, 2008, after William received his RAF wings from his father, the Prince of Wales.

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June 2008: Middleton attends the Order of the Garter service at Windsor Castle, the first time she has appeared at a formal royal public event.

Photo: Kate Middleton is pictured in Windsor, England, on June 16, 2008, to watch her boyfriend Prince William join other members of the royal family as a Knight of the Garter.

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February 2010: Asked by a member of the public about the prospect of a royal wedding, William says: "You'll have to wait a while yet."

Photo: Prince William as Commodore-in-Chief-Submarines attends a ceremony to hand out silver and gold pins to sailors at HMNB Clyde naval base on Oct. 28, 2010, in Faslane, Scotland.

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October 2010: Prince William proposes to Kate Middleton on a private holiday in Kenya.

Photo: Britain's Prince William and Kate Middleton leave the wedding of their friends Harry Mead and Rosie Bradford in the village of Northleach, Gloucestershire, England, on Oct. 23, 2010.

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November 2010: Clarence House officially announces the engagement.

Photo: Britain's Prince William and fiancee Kate Middleton pose for the media at St. James's Palace in London, Nov. 16, 2010, after they announced their engagement.

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December 2010: William and Middleton attend a charity event to raise money for cancer research. It's her first official event as a royal fiancee.

Photo: Britain's Prince William and his fiancee, Kate Middleton, arrive to view the Thursford Christmas Spectacular gala in Thursford, England, Saturday, Dec. 18, 2010.

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Mario Testino/Clarence House Press Office via Getty Images

February 2011: First wedding invitations sent out.

Photo: Prince William and Kate Middleton pose in the Council Chamber in the State Apartment in St. James's Palace in London on Nov. 25, 2010.

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February 2011: William and Middleton revisit St. Andrews University, where they first met. The university created a scholarship in the couple's honor, as a wedding gift.

Photo: Prince William and Kate Middleton wave as they pass St. Salvator's hall, during a visit to St. Andrews University, Scotland, Feb. 25, 2011.

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March 2011: The royal couple visits Northern Ireland as part of their pre-wedding tour of the United Kingdom.

Photo: Britain's Prince William and his fiance Kate Middleton leave City Hall in Belfast, Northern Ireland, on March 8, 2011.

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April 2011: William and Middleton visit Lancashire on their last official trip before the wedding on April 29.

Prince William and Kate Middleton arrive at Witton Country Park in Darwen, England on April 11, 2011.

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