The Queen won't be attending great-grandson Archie's christening

Prince Harry and Meghan Markle have reportedly chosen a date in July for the baptism of Baby Sussex. Photo / Getty Images

Baby Archie will be baptised next month, despite the fact that one very important guest, his great grandmother, the Queen, is not able to attend.

The Sunday Times reports that due to prior commitments the Queen won't be at the baptism held at St George's Chapel in Windsor Castle, where his parents were married last year.

Six-week-old Archie Harrison Mountbatten-Windsor will be two months old in July and it's expected his first ceremony will see a large turn-out.

It's assumed that the Queen will not attend the service. Photo / Getty Images

According to The Sun, the rest of the family will be there to make up for the Queen's absence with Prince Charles and Camilla, Duchess of Cornwall, leading the party, as well as the Duke and Duchess of Cambridge.

This won't be the first time the Queen skips one of her great grandchild's baptisms.

The Queen attended Princess Charlotte's baptism, but not Prince Louis'. Photo / Getty Images

Last year, she didn't attend Prince Louis' christening but did go to the ceremonies for his elder siblings, Prince George and Princess Charlotte.

The Sunday Times reports that the ceremony will follow royal tradition, and will be similar to Archie's father Prince Harry's service, held at the same place in 1984, when he was 3-months-old.

The Sussex's posted a picture of Archie in honour of Father's Day. Photo / Instagram

Archie is expected to wear a replica of the Honiton lace gown which was first commissioned by Queen Victoria for her first daughter Princess Victoria's christening in 1841.

The gown was worn by 62 royal babies - including Harry and William, 36 - until the Queen decided it was too fragile and a replica was made.

Prince Harry wore the Honiton christening gown in for his baptism in 1984. Photo / Getty Images

The Sun reports that the service will likely be conducted by the Dean of Windsor, the Rev David Conner and the Archbishop of Canterbury.

In July when we get another glimpse of Archie he'll be two months old. Photo / Getty Images

Rumours surrounding who Archie's godparents could be include names such as Meghan's best friend, Jessica Mulroney, American designer Misha Nonoo and Harry's friends from school, Alexander Gilkes and Jake Warren.