Why Prince George and Princess Charlotte weren't on the Royal balcony

The royal family has gathered for the 100 year anniversary of the Royal Airforce (RAF) in London, appearing on the balcony at Buckingham Palace for an impressive display.

However Prince George and Princess Charlotte didn't join the Duke and Duchess of Cambridge who stood with Queen Elizabeth, the Duke and Duchess of Sussex and the Duke and Duchess of Cornwall for the event.

Instead, the cheeky young royals were spotted through a window at the palace, making faces and poking their tongues out, much to the delight of the gathered crowd.

In one photo, Prince George and Princess Charlotte can be seen pressing their faces to the window, watching the event unfold.

In another, Princess Charlotte shields her eyes as she and her brother look in different directions at the awaiting crowd. 

Soon the young royals began dancing, much to the delight of those watching.

Princess Charlotte seemed impressed by Prince George's dance moves. 

Eventually the young royals looked bored, with Princess Charlotte having a nice, big stretch.

Kate Middleton is still on maternity leave after giving birth to Prince Louis just 11 weeks ago, however it is understood she felt the celebration was too important to miss.

Prince Louis was christened at St James's Palace yesterday so it has been a busy week for the royal family.

Today marks the 100 day RAF centenary, with the Royal Flying Corps and the Royal Naval Air Service merging to form the organisation on April 1, 1918, to create the world's first independent air service.

Her Majesty presented a new Queen's Colour to the RAF at the event, paying tribute to the "tenacity, skill and gallantry" of those who served.

The Queen spoke proudly as the RAF's Air Commodore-in-Chief and also in remembrance of the Battle of Britain, in which her father King George VI served.

Just after 1pm there was an incredible display involving Puma and Chinook helicopters followed by aircraft including a Lancaster, Spitfires, Hurricanes, the A400M Atlas Tornados and three F-35 stealth fighter jets.

The royals gathered on the balcony at Buckingham Palace for the display, following a service at Westminister Abbey.

Prince Philip was unable to attend the event, with the 97-year-old stepping down from public engagements last year.

Neither the Duke of Edinburgh or the Queen attended the christening of their great grandson Prince Louis this week, as they were  travelling back from Norfolk.