Prince Harry and Meghan Markle won't be attending Prince Charles' birthday party.

Meghan and Prince Harry

Meghan and Prince Harry

Starting next month, the Duke and Duchess of Sussex will embark on their first royal tour - which will see the newlyweds leaving on October 16 and returning at the beginning of November - meaning they will miss the Duke of Cornwall's 70th birthday festivities.

In celebration of the milestone, Camilla - the Duchess of Cornwall is reportedly arranging a special concert and dinner at Buckingham Palace on October 25th - although his actual birthday isn't until November 14th.

The couple's tour will include visits to Australia, New Zealand, Fiji, and the Kingdom of Tonga, and Harry, 34, and Meghan, 37, will be in Tonga during the celebration.

An insider previously explained: "They wanted to hit the ground running after their marriage to focus on their charitable interests and Meghan is really looking forward to representing Her Majesty on her first major Commonwealth tour."

The former 'Suits' actress retired from acting prior to her wedding, but she's relishing the challenge of her new role.

The source told 'Entertainment Tonight': "She really is taking the new job part of her role seriously having meetings with Palace staff and learning about the Commonwealth so she can support Harry in his new role as Commonwealth Youth Ambassador."

Although the couple - who tied the knot at St Geroge's Chapel at Windsor Castle in May - are currently focused on their public service, the pair are reportedly "eager to start a family"

The insider said: "Harry is tactile and protective of his new wife. He is completely besotted and nothing would make him happier if they were starting a family."