The royal milestone that Prince George and Princess Charlotte will miss this week

The Cambridges have been very busy in lockdown. As well as making spider sandwiches, Prince William and Kate Middleton have been making video calls to NHS workers and Prince George and Princess Charlotte have been delivering food to the most vulnerable.

But many royal events have been cancelled as a result of the Covid-19 pandemic, including the Queen's annual birthday gun salutes and many of them - from Prince Louis and Princess Charlotte, to Prince Philip - have spent their birthdays in lockdown.

However, the Trooping the Colour parade, which is held for the Queen's second birthday, will also been adapted to adhere to to the government guidelines on social distancing.

Every year, crowds gather along The Mall and all the way up to Buckingham Palace to watch the royals pass by in carriages as part of their procession, and later appear on the balcony to watch the fly-past and wave.

The scaled back event will this year be held at Windsor Castle, where the Queen is currently isolating.

Prince William was weeks away from his 5th birthday when he made his royal carriage debut in 1987, alongside Princess Diana and Prince Charles, and the Queen Mother. Similarly, Prince Harry was almost five when he was first part of the procession in 1989.

It was believed that Prince George and Princess Charlotte might also appear in their first carriage procession as the eldest Cambridge child is now six years old, and his sister is five.

Due to the cancellation of the annual event in its traditional form, it is unclear who will attend.

The little royals were expected to make their debut last year, but Kate instead rode alongside the Duke and Duchess of Sussex, Prince Harry and Meghan Markle, and Camilla, Duchess of Cornwall.

The crowds did get to see Prince Louis make his first balcony appearance in 2019, as he adorably waved at the fly-past.

Hopefully George and Charlotte will make their carriage debut next year!