The fab four, as they’ve been dubbed, are set to be reunited next month at a special reception to mark the 50th anniversary of the investiture of the Prince of Wales.
Kate, William, Meghan and Harry will celebrate the occasion at Buckingham Palace on 5 March, hosted by the Queen.
They’ll also be joined by Charles’ wife Camilla, Duchess of Cornwall and his sister Princess Anne.
William and Harry are also planning to formally split their royal household “within weeks,” in order to reflect their different responsibilities and areas of interest.
A source told The Sunday Times: “When William becomes the Prince of Wales, he will take on a lot of extra responsibility, including the Duchy of Cornwall. Harry and Meghan have none of that, and seem ambitious about forging their own paths.
“If you have one private office trying to manage both, things get difficult. William and Harry’s double act has naturally been supplanted by the two couples and their families.”
The Royal Family tend to get together for annual events such as Trooping the Colour, Commonwealth Day and Remembrance services, as well as personal celebrations like weddings and christenings.
Prince Charles was created the Prince of Wales aged 9 on July 26 1958, but wasn’t formally invested with the title until July 1 1969 at Caernarfon Castle.
Buckingham Palace said the reception will also be “an opportunity to celebrate a range of Welsh charities, organisations and businesses.”
Among the guests will be leading figures in Welsh and UK public life, as well as representatives from the prince’s many Welsh charities and patronages, including The Prince’s Trust Cymru.
There will also be a musical performance in the Ballroom by students from the Royal Welsh College of Music and Drama.