Queen knights Prince Philip in special Australian investiture ceremony

The Queen had a particularly special investiture ceremony on Wednesday: her husband, Prince Philip was the recipient. The Duke of Edinburgh received the insignia of a Knight of the Order of Australia medal during a Windsor castle ceremony which was also attended by Australia’s high commissioner in the UK, Alexander Downer.

The ceremony was short and held in the white drawing room at midday.

Prince Philip inspects his new honour

"The Queen today invested the Duke of Edinburgh with the insignia of a Knight of the Order of Australia at Windsor Castle," said Buckingham Palace in a short statement.

Philip's knighthood was first announced in January, when Australian Prime Minister Tony Abbott revealed that the Queen had agreed to the recommendation.

Australia only restored knights and dames back into the honours system in 2014, 30 years after they were abolished.

Alexander Downer (right) handed over the medal to the Queen

The ceremony comes a day after the Queen celebrated her 89th birthday – and royal watchers would have been hoping for double festivities, as the Duchess of Cambridge prepares to welcome her second child any day.

The Duchess, née Kate Middleton, has refused to confirm her exact due date for royal baby number two, but the new arrival could now coincide with one of two special dates if born in the next week – St George's Day on 23 April, or Prince William and Kate's wedding anniversary on 29 April – serving as the ultimate anniversary gift for the royal couple.

Australia only reinstated knighthoods in 2014

Preparations are already being made outside the exclusive Lindo Wing at St Mary's Hospital in London, with royal enthusiasts gathering in anticipation of Kate's due date.

Speaking to HELLO! Online, one of the fans, Margaret Tyler, an avid collector of royal memorabilia, said: "I am very excited, over the moon."

"I am mostly going to be here until it all happens," added Margaret. "I wake up every night to put the TV on to check if anything has happened."