The first international visit by the Duke and Duchess of Cambridge, a.k.a William and Kate, has major implications for the future of the British House of Windsor in all of its institutional reach.
But the tour of the next generation of Royals also has significance for the links between transnational celebrity culture and humanitarian affairs.
For all the talk about the need to rebrand the monarchy, from a diplomatic perspective what jumps out is the traditional nature of the exercise.
In Canada, the "senior realm" of the British Commonwealth, the state-centric orientation of the trip was made explicit from the moment William and Kate got off the Canadian Forces plane flying them from London to Ottawa.
The immediate focal point was their attendance at the July 1 Canada Day celebrations on Parliament Hill in which the dominant theme was of the "unbeatable spirit" of the country.
In words hardly distinguishable from those that would have been used by earlier generations of Royals, William -- a search and rescue pilot with the Royal Air Force -- was most expansive in his speech on the military component of Canada's history, with special reference to the winding down of the Canadian combat role in Afghanistan. Along with Vimy Ridge, Juno Beach, Korea and the Balkans, this was said to be "an episode of which all Canadians can be immensely proud."
Although more commercial than geo-political, the U.S. non-Commonwealth component of the trip also contained strong elements of service to the state. The three-day visit to California was initiated by a Consular-General Reception in Los Angeles on behalf of United Kingdom Trade and Investment: a government department that looks after British business interests and start-ups overseas. It also featured a British Academy of Film and Television Arts event designed to spotlight up and coming British talent.
Yet the extended list of William and Kate's activities reveals the hybrid nature of the young Royals concerns, a mix that demonstrates very strongly the fact that they are influenced not only by state interests but by global celebrity culture.
In this arena, the influence is more the Duke's late mother, Princess Diana (who in a poignant twist would have been 50 years old on July 1), the original "Peoples' Princess".
Akin to Princess Di, William and Kate are at home in the company of other mega-celebrities such as David Beckham who they met again in California.
Nor is this relationship grounded only about fashion!
William follows in his mother's footsteps in a number of substantive causes, including taking on the position as the Patron of Centrepoint, the U.K.'s leading homelessness charity.
Connections with this local humanitarian agenda were made in the California trip with visits to Skid Row and to a job fair for U.S. servicemen and women transitioning to civilian life.
The big question is whether tension will appear for the young Royals between their traditional state connected activities and a more diverse humanitarian agenda.
As is well known, Princess Diana consolidated her mega-celebrity iconic status by rebranding herself as the champion of the anti-personnel landmines campaign working with the Red Cross and the HALO Trust.
Given the stimulus of the star power William and Kate have demonstrated in North America, the attractions of rebranding themselves in a similar global manner will loom large.
Yet as the experience of Princess Diana witnessed, such efforts bring out tensions between celebrity humanitarianism and institutional duties.
How these tensions will be reflected and if they will be resolved is a serious theme that deserves at least as much attention as the immediate buzz created by the 11-day tour by the young Royals.