Britain's Prince Harry and his wife Meghan, Duchess of Sussex, at a garden party at Buckingham Palace with Prince Charles and Camilla the Duchess of Cornwall
Britain's Prince Harry and his wife Meghan, Duchess of Sussex, at a garden party at Buckingham Palace with Prince Charles and Camilla the Duchess of Cornwall, their first royal engagement as a married couple, in London, May 22, 2018. Dominic Lipinski/Pool via Reuters

Prince Harry and Meghan Markle won’t attend Prince Charles’ birthday celebration. They have a good reason, though.

The future king will turn 70 in November, and his wife Camilla, Duchess of Cornwall, has organised an early party with family and friends for him on Oct. 25. His elder son, Prince William, is expected to attend with his wife, Kate Middleton, whose six-month maternity leave ends next month.

His younger son and his wife, however, won’t be in attendance, but it’s nothing personal. The Duke and Duchess of Sussex will be embarking on their first official overseas trip together in Australia, New Zealand, Fiji and the Kingdom of Tonga starting October. The couple won’t be back in the UK until their tour ends on Oct. 31.

“It’s going to be a very special night and Charles is very much looking forward to it,” a source told Vanity Fair. “Harry and Meghan can’t be there because they will be overseas. It’s why they were so keen to be at the garden party for Charles back in May.”

The garden party in May was Charles’ 70th birthday patronage celebration. It was just a few days after Harry and Meghan’s royal wedding on May 19. But while Harry and Meghan were there, William and Kate were not.

The Cambridges also had good, separate reasons why they did not attend the event. William was speaking at a tribute to the Manchester Arena bombing victims at Manchester Cathedral on the same day. Kate, on the other hand, was still on maternity leave, having given birth to their youngest child, Prince Louis, just a month before.

Charles’ sons and their wives are all expected to attend another celebration on his actual birthday on Nov. 14. Queen Elizabeth will host a party in the State Rooms of the Buckingham Palace for her heir.