Princess Charlotte melted hearts with one simple gesture during a carriage ride in the midst of a rainy Trooping the Colour.

Following the outstanding parade performed by soldiers at Horse Guards Parade under the attentive eye of King Charles and Queen Camilla, the royals headed to Buckingham Palace before the much-anticipated balcony appearance.

Princess Charlotte shared the carriage for this brief ride with her mum Kate, Princess of Wales, and brothers Prince George and Prince Louis.

The rain pouring down in London on Saturday caused the carriages’ windows to become foggy, making it impossible for the public to see the young royals waving at them.

But Princess Charlotte saved the day and, as the carriage approached the Queen Victoria Memorial outside of Buckingham Palace, she wiped the fog off the glass with her hand.

The nine-year-old could be seen smiling while cleaning out the window with the help of her doting mum Princess Kate.

A BBC journalist commentating on the event said: “You can see the Princess of Wales and Princess Charlotte trying desperately to clean that fog off the glass so they can see and so the public can see them.”

Wearing an adorable dark blue dress with white details, Charlotte looked poised as she stood alongside her mum and siblings by the windows of the Major General’s office overlooking Horse Guards Parade.

Her younger brother Louis, on the other hand, was back to his cheeky antics, as he was spotted chatting with Princess Kate, yawning and even playing with a blind cord.

This year’s Trooping the Colour marks the second parade marking the official birthday of the monarch being celebrated by King Charles.

The King, who is undergoing therapy for an undisclosed form of cancer, didn’t take part in the parade on horseback but, rather, watched it on a dais with Queen Camilla at his side.

Today also marked the first official public appearance since Christmas Day of Kate, who is also undergoing treatment following a cancer diagnosis she received at the beginning of the year.