The Duke and Duchess of Cambridge begin their tour of New Zealand and Australia with their baby Prince George on Monday.
The Cambridges will travel across the two nations over 19 days celebrating the people, culture and institutions of the Commonwealth countries.
With the eight-month-old Prince joining his parents on the tour, it will echo the Prince and Princess of Wales' 1983 trip to Australia and New Zealand, when the couple took William, then just nine-months-old, with them.
George will be seen in public at least four times when he embarks and disembarks in the two countries but he is likely to attend a couple of events on the tour, one in each country.
He is expected to join his parents on Wednesday at an event for nurses, parents and young children from the Plunket Parents Group, an organisation that provides health care and support to new families.
Miguel Head, William's private secretary, speaking about the royal couple's decision to bring their baby on tour, has said: "Like any new parents they wanted to ensure that the decision was theirs and it wasn't driven by any other people's expectations.
"They have come to the decision because it is a long way to go and for a long time - three and a half weeks including the travel - and it's a decision that they feel comfortable with.''
The Queen has given approval for William and George, two immediate heirs to the throne, to travel together on the trip - they would not have been permitted to fly in the same plane without her say so.
Officials have confirmed that the programme of events has been tailored to accommodate the fact that the couple have a baby with them.
Mr Head has said the Cambridges had planned a "hub and spoke" system for their tour, by largely basing themselves in three locations - Wellington, New Zealand and Sydney and Canberra in Australia - and visiting various parts of the countries before returning to stay with their son.
He said: "That's so that Prince George doesn't have to move around and the couple can cover as much as they can."
William has travelled to Australia and New Zealand a number of times but Kate has yet to pay an official visit - although she and her husband created a stir in September 2012 when they flew to Brisbane airport to catch a flight home at the end of their South Pacific tour.
The second-in-line to the throne has said he wishes to show his wife the two countries - which have close ties with the UK.
Mr Head said: "There is no hiding the enthusiasm for this visit by both the Duke and The Duchess. The Duke, because he has been before and the Duchess because she has never been to either country but has wanted to do so as long as she can remember.
"The Duke has no doubt that his wife will fall in love with New Zealand and Australia every bit as much as he did, some years ago.''
He added: "It's a tremendously exciting visit and I can tell you their Royal Highnesses are looking forward to it immensely.''
The trip will end on Friday, April 25 - just four days before the Duke and Duchess celebrate their third wedding anniversary.
William's last official trip to New Zealand and Australia was in March 2011, when he visited Christchurch, shortly after it suffered an earthquake, and the Australian states of Queensland and Victoria, which had been hit by floods.
In January 2010 he represented the Queen at the opening of the Supreme Court building in Wellington and also visited Auckland, and during the same trip travelled to Melbourne and Sydney.
The latest action-packed tour reflects the "outdoorsy and sporty'' people that William and Kate are.
There is an eclectic mix of events including a trek around Uluru (Ayers Rock), a fast-boat river ride and meeting some of the All Blacks Rugby World Cup champions. The couple will also participate in a boat race - on opposing teams.
They will also meet Sir Peter Jackson, maker of the Lord Of The Rings and The Hobbit trilogies.
But the visit also includes more formal events with politicians and military personnel - though there are no black tie occasions.
And no royal tour would be complete without the ceremonial planting of a tree.
Kate will also visit children's hospices in each country - continuing her charitable interest in palliative care for youngsters.
In New Zealand the royals will visit Wellington, Auckland and Christchurch among other places.
Australian highlights include Sydney, Brisbane, Adelaide and Canberra - but not Melbourne or Perth.
The royal couple will arrive at Wellington Airport in the early hours of Monday before receiving a formal welcome from the Governor General of New Zealand Jerry Mateparae at Government House in the capital Wellington.
Rebecca Deacon, Kate's private secretary, Mr Head, three press officers, a tour secretary, an orderly and adviser Sir David Manning will be part of the royal party during the tour.
The royal entourage will also include a hairdresser and a personal assistant.