The Duke and Duchess of Cambridge and their children have arrived in Poland, the first leg of a goodwill trip to two European Union nations that seeks to underscore Britain's friendly ties despite its negotiations to leave the bloc.
Their five-day tour of the two European countries is at the request of the Foreign and Commonwealth Office.
But all eyes will be on the couple's children, George aged three and two-year-old Charlotte, who are getting used to travelling overseas having joined their parents in Canada a year ago for an official trip.
For their parents, the visit to Poland and then to Germany will inevitably be viewed in the context of Brexit.
On their first official visit to Poland they have come with their children, Prince George, who will be 4 on Saturday, and Princess Charlotte, 2.
"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", a Kensington Palace spokesman said.
Prince William and Kate will also meet survivors of the Holocaust and Nazi oppression.
It will, the Foreign Office hopes, remind people of the strength of the ties that will endure after the United Kingdom has left the EU. The couple, along with other members of the royal family, have visited a number of European countries in recent months in what is being called a "Brexit royal charm offensive" as the United Kingdom negotiates its withdrawal from the European Union.
In Poland, they will tour the former Stutthof concentration camp where 65,000 people died, and tour the site of Gdansk's shipyards, the birthplace of Poland's Solidarity movement that helped topple Communist rule.
In Germany, William and Kate are planning to meet with German Chancellor Angela Merkel, visit Berlin's Brandenburg Gate, enjoy a traditional beer garden in Heidelberg and pay a somber visit to Berlin's Holocaust Memorial.
Perhaps the penultimate event of the royal tour will be when William and Kate take their competitive streak to the water as they captain crew boats in Heidelberg.