It is a job that Prince William will one day undertake on his own, but for now, the 32-year-old second-in-line to the throne was happy to stand back and watch as Queen Elizabeth II met with several Ambassadors from around the globe. The Queen, who has been on the throne since 1952, holds scores of audiences every year.
On Wednesday Her Majesty met with the Ambassador of the Republic of Nicaragua, Her Excellency Ms Guisell Morales-Echaverry, and the Ambassador of Austria, His Excellency Dr Martin Eichtinger.
William's appearance at the meeting is reportedly not an indication that the Prince will start performing this role.
Prince William stood and watched as his grandmother carried out royal duties
Although William stood back for most of the duration of the audience, he did shake Dr Eichtinger's hand and shared a laugh with Ms Guisell Morales-Echaverry.
William joining his grandmother is another sign of the Queen beginning to hand over more responsibility to Prince Charles and William.
Early in 2014 Buckingham Palace began to merge staff, with Prince Charles, who will inherit the throne when the Queen passes, seeing his aide become the media chief for the entire Royal household.
Prince William is beginning to learn more about his future royal duties
William, who became a father for the first time on 23 July 2014, is preparing to welcome his second child with wife the Duchess of Cambridge.
The pair have had the nation guessing on Kate's due date, with some punters placing bets that she will give birth as early as March, but speaking at a charity engagement at a children's centre in Woolwich on Wednesday, Kate gave more of a clue as to when her child will be born – "mid-to-end of April" – according to one volunteer.
"I told her she is beautiful and that she's got a tiny little bump," said volunteer Christie Osborne, 49. "I asked when her baby is due and she said mid-to-end of April."
Kate, who was pictured cradling her baby bump during the engagement, was also overheard saying: "Not long to go now."