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Princess Beatrice and Princess Eugenie -

Princess Beatrice accompanies her sister, Princess Eugenie, on her first day at Upton House School in Windsor, England, in 1994.

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Prince William and Prince Harry -

The Prince and Princess of Wales pose for a picture with their kids, with the adorable Prince William and Prince Harry wearing white and blue.

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Prince George and Princess Charlotte -

Prince George and Princess Charlotte wave in their burgundy clothes as they depart Victoria, Canada, on October 1, 2016.

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Princess Leonor and Princess Sofia -

King Felipe VI and Queen Letizia of Spain pose with their children, Princess Leonor and Princess Sofia, on December 10, 2018 in Madrid.

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Princess Catharina Amalia, Princess Ariane, and Princess Alexia -

King Willem Alexander and Queen Maxima of the Netherlands and their daughters greet the crowd on the balcony of the Royal Palace on April 30, 2013 in Amsterdam.

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Prince George and Princess Charlotte -

Isn't it lovely when the whole family color coordinates? The Cambridges is shades of lilac and pink, in Hamburg, Germany, on July 21, 2017.

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Princess Beatrice and Princess Eugenie -

The two sisters attend the Christmas pantomime 'Cinderella' in aid of Children in Crisis, of which their mother is a patron.

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Infanta Cristina, Crown Prince Felipe, and Infanta Elena -

The Spanish royals wearing blue on vacation at the Miravent Palace in Palma de Mallorca, Spain, on October 15, 1976.

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Queen Elizabeth II and Princess Margaret -

The then-Princess Elizabeth and Princess Margaret pose for a photo in matching outfits at Buckingham Palace in 1942.

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Prince Charles and Princess Anne -

Queen Elizabeth II poses with her children at Balmoral, in 1952.  How adorable are Charles and Anne's outfits?

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Prince Jacques and Princess Gabriella -

Prince Albert II of Monaco is pictured with Prince Jacques and Princess Gabriella, as well as Kaia-Rose Wittstock, niece of Charlene, Princess of Monaco, at the F1 Grand Prix of Monaco on May 25, 2019. We love the shades!

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Princess Beatrice and Princess Eugenie -

The sisters do it again. This time, at the Theatre Royal in Drury Lane, London, in 1998.

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Zara and Peter Phillips -

Princess Anne with her children at the Windsor Horse Trails, as you can see by the logos on their sweaters!

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Prince William and Prince Harry -

Prince William accompanies his little brother on his first day at Wetherby School on September 11, 1989.

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Princess Beatrice and Princess Eugenie -

The Duchess of York really liked to dress up her children in matching outfits. Here they are again at a film premiere in 1996.

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Prince Charles and Princess Anne -

A young Charles and his sister are pictured playing at Balmoral Castle in Scotland on September 28, 1952.

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Prince William and Prince Harry -

Diana, Princess of Wales is pictured with her sons wearing matching outfits at Aberdeen Airport in 1989.

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Princess Leonor and Princess Sofia -

The Spanish royal family poses for the official Christmas photo in 2009.

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Princess Beatrice and Princess Eugenie -

The Duke and Duchess Of York pose with their daughters, who, once again, are coordinating outfits.

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Prince William and Prince Harry -

How adorable do Prince William and Prince Harry look in army uniforms? This photo was taken at Highgrove House on July 18, 1986, in Tetbury, England.

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Queen Elizabeth II and Princess Margaret -

The sisters make a broadcast to the children of the Empire during World War II, in October 1940. Not only were they wearing matching outfits, but they also styled their hair in the same fashion.

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Princess Beatrice and Princess Eugenie -

The sisters do it again! Here with cousins Princes Harry and William at Klosters, Switzerland in 1995. Check out Prince Harry wearing a bandana! 

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Prince William and Prince Harry -

Prince Harry and William wave in all-denim and baseball caps, in Canada, circa 1991.

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Prince George and Princess Charlotte -

Princess Charlotte and Prince George looking adorable at the wedding of Princess Eugenie to Jack Brooksbank at St George's Chapel in Windsor Castle on October 12, 2018.

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Queen Elizabeth II and Princess Margaret -

Princesses Elizabeth and Margaret leave  Westminster Abbey in London, after a rehearsal for the coronation of their father as King George VI, on May 6, 1937.

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Prince William and Prince Harry -

Prince William and Prince Harry in matching outfits watch their father play polo at Guards Polo Club in 1987.

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Princess Beatrice and Princess Eugenie -

Princess Beatrice and Princess Eugenie in their cute ballerina outfits at 'Santa's Starry Night Show' in London.

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Juan Valentín, Pablo Nicolás, Sebastián, Miguel, and Irene -

Spanish royals Princess Cristina, husband Iñaki Urdangarin, and their children, all wearing matching outfits at Marivent Palace on August 8, 2006, in Mallorca, Spain.

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Prince William and Prince Harry -

The royal brothers smartly dressed at Zurich airport, ahead of their skiing vacation in Klosters, Switzerland in 1996.

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Princess Beatrice and Princess Eugenie -

The Duke and Duchess of York with their children at the Windsor Horse Show in 1992.

See also: The British royal family at the races

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