Prince George and Princess Charlotte will join the Duke and Duchess of Cambridge on their tour of Poland and Germany.
The older royals are making the trip at the request of the Foreign and Commonwealth Office, as part of an effort to maintain good relations with European countries despite Britain's impending exit from the European Union.
However, Prince George, three, and his younger sister, Princess Charlotte, two, are likely to be the centre of attention during the tour.
The duo will only be seen at certain events, but their appearances seem set to create lots of attention, with Kancelaria Prezydenta, the Polish President, having already posted images of the toys that the young royals will be able to enjoy during their stay on Twitter.
Meanwhile, a Kensington Palace spokesman has explained that the Duke and Duchess are excited to be travelling to Poland and Germany with their children.
The spokesperson said: "The Duke and Duchess are very much looking forward to this tour and are delighted with the exciting and varied programme that has been put together for it.
"They have decided that their children, Prince George and Princess Charlotte, will travel with them and we expect the children to be seen on at least a couple of occasions over the course of the week."
The royals' five-day trip will start with a welcome from President Duda in the Polish capital Warsaw.