The British royals and the Obamas: A photo timeline of their moments together

April 2009A historic introduction: President Obama and Michelle met Queen Elizabeth for the first time almost a year after taking office. Royal and political watchers around the world had their eye on the special occasion which saw the Queen "break protocol" for the first time in a number of years when she and the first lady shared a small embrace. Photo: Pete Souza/White House via Getty Images

President Obama, Queen Elizabeth, Michelle Obama and Prince Philip gathered together after their initial introduction at Buckingham Palace.Photo: John Stillwell - WPA Pool/Getty Images

May 2011 Michelle and Barack returned to London in the spring to meet once again with the Queen and Prince Philip. Photo: Toby Melville - WPA Pool/Getty Images

For their first act of royal duties as husband and wife, Prince William and Kate Middleton attended a special lunch held during POTUS and FLOTUS' two day visit.Photo: Charles Dharapak/Getty Images

Michelle and Kate chatted it up (in style) ahead of a special lunch. The luncheon was the first time the royal couple met America's first couple. Photo: Charles Dharapak/Getty Images

The Duchess of Cornwall dressed to impress as she left Winfield House with Michelle. Photo: Dominic Lipinski - WPA Pool/Getty Images

Queen Elizabeth and President Obama were photo ready while Michelle and Philip were caught in a candid moment during the State Banquet at Buckingham Palace.Photo: Chris Jackson - WPA Pool/Getty Images

Cheers! President Obama and Queen Elizabeth raised a glass in honor of each other during the banquet. Photo: Lewis Whyld - WPA Pool/Getty Images

July 2012Barack and Will's leading ladies reunited during a reception in London for the Olympics. Photo: Dominic Lipinski - WPA Pool/Getty Images

May 2013 Prince Harry made a surprise visit to an event honoring military parents during his trip to Washington, D.C. Photo: Mark Wilson/Getty Images

Prince Harry and Michelle sat with children who were making presents for their mothers during an event honoring military families. Photo: John Stillwell - WPA Pool/Getty Images

October 2015Michelle, Harry and second lady Dr. Jill Biden shared a laugh during a presentation at the USO Warrior and Family Center at Fort Belvoir, Virginia. Photo: Saul Loeb/Getty Images

Harry and Michelle had a ball during his trip to the nation's capital where he discussed his Invictus Games coming to Orlando.Photo: Saul Loeb/Getty Images

April 2016The President and Mrs. Obama received a warm welcome from Queen Elizabeth and Prince Philip when their helicopter arrived at Windsor Castle. After their meeting on the lawn, Prince Philip drove the Obamas to the Sovereign's Entrance in the Quadrangle for a special luncheon. The trip marked the final time the president and first lady met with the Queen and her family as head of state. Photo: Jack Hill/Getty Images

Ahead of their special birthday lunch in honor of the Queen turning 90, the royal couple and the first couple showed off their pearly whites.Photo: John Stillwell/Getty Images

POTUS and FLOTUS were welcomed by Prince William, Prince Harry and Kate Middleton for a dinner at Kensington Palace. Photo: Chris Jackson/Getty Images

The ever-charming Harry welcomed the first lady with a kiss on the cheek. Photo: Chris Radburn - WPA Pool/Getty Images

During dinner, the first lady and Kate shared a girls' moment inside the Drawing Room of Apartment 1A in Kensington Palace. Photo: Dominic Lipinski - WPA Pool/Getty Images

What an honor! President Obama was treated to a special meeting with Prince George. The then two-year-old was allowed to stay up past his bedtime (but didn't change out of his sleep attire) to meet the president and the first lady. Photo: Pete Souza/The White House

June 2015 Michelle found a moment to catch up with her royal friend Harry at Kensington Palace while on tour for her Let Girls Learn initiative. Photo: Amanda Lucidon/The White House via Getty Images

May 2016: Game on! One month following her trip to London, Michelle was joined by Harry and GMA's Robin Roberts in Orlando for the 2016 Invictus Games. After months for playful (yet competitive) banter, and the Queen's epic mic drop, the duo reunited for the final time to face off in the sporting event dedicated to wounded warriors. Photo: Chris Jackson/Getty Images for Invictus Games

Never letting their competitive edge get in the way of their friendship, Michelle greeted Harry on stage during the opening ceremony of the 2016 Invictus Games. The first lady praised Harry for all his hard work, telling the crowd "He is truly our Prince Charming isn't he? He should be proud of himself for his work." Photo: Gustavo Caballero/Getty Images for Invictus Games

MAY 2017: Just in the neighborhood! The former president stopped by to say hello to his good friend Prince Harry at Kensington Palace on May 27. Photo: Getty Images

SEPTEMBER 2017Prince Harry had some company at the Invictus Games Toronto! Former President Barack Obama (along with former Vice President Joe Biden, along with his wife Dr. Jill Biden), dropped by the Pan Am Centre to catch a wheelchair basketball game on day 7. The two men were overheard chatting about Harry’s girlfriend Meghan Markle, who stars in US TV drama Suits.Photo: Karwai Tang/WireImage

October 2017Prince Harry touched down in Chicago on October 31 to participate in the Obama Foundation's inaugural summit. The royal joined Michelle Obama to drop in on some unsuspecting students at Hyde Park Academy. During the hour-long visit, Michelle and Harry chatted with the future leaders about staying positive in the face of adversity and the "transformative power of students using their voices to change the world." Photo: Instagram/@michelleobama