Kate Middleton and Prince William
Kate Middleton made an official visit to Luxembourg without Prince William in 2017. Pictured: Middleton and Prince William attend the Men's Singles final on day thirteen of the Wimbledon Lawn Tennis Championships at All England Lawn Tennis and Croquet Club on July 15, 2018 in London. Getty Images/Clive Brunskill

Kate Middleton is not afraid to make an official visit on her own.

According to Kara Godfrey, a journalist for Express, the Duchess of Cambridge made a solo trip to Luxembourg without Prince William in 2017. Middleton visited the country for the 1897 Treaty of London to mark the 150th anniversary of the country's independence.

It was an official visit at the request of Her Majesty's government. Middleton left Prince George and Princess Charlotte at home with Prince William.

For the said trip, Middleton met Prime Minister Xavier Bettel and Crown Princess Stephanie. She also visited Musze d'Art Moderne, Grand Duke Jean Museum of Modern Art and Drai Eechelen Museum. She was photographed wearing a pastel blue coat dress by Emilia Wickstead. She paired it with nude heels.

It was the second solo trip Middleton has undertaken. In 2016, she visited the Netherlands without Prince William. The Duchess of Cambridge was spotted at The Hague and Rotterdam. She was seen returning to the UK by British Airways.

Just like Meghan Markle, Middleton loves traveling, too. In fact, the Duchess of Cambridge visited more countries than her sister-in-law. Middleton has already visited 25 countries already. On the other hand, the Duchess of Sussex has already traveled to 15 countries including Spain, Italy, Greece and Malta.

When Middleton and Prince William broke up, she also took it as an opportunity to travel to Ireland. Middleton flew to Dublin with her mom, Carole.

During their trip, they visited her first exhibition at the Urban Retreat Gallery and National Gallery of Ireland. They also met Irish artist Gemma Billington, a family friend, who was among Prince William and Middleton' guests at their royal wedding in 2011.

Middleton met a few reports during the said outing but "politely declined" to say a few words to them. During their engagement interview, the duchess opened up how she was affected by their split.

"I think I at the time wasn't very happy about it, but actually it made me a stronger person," Middleton said. "You find out things about yourself that maybe you hadn't realised. Or I think you can get quite consumed by a relationship when you are younger."