The impending retirement of the Duke of Edinburgh from public duties is a watershed moment for the British monarchy, and for New Zealand.
The Queen's husband had been a fixture at her side through almost 70 years of marriage. The announcement that Prince Philip, who turns 96 next month, would withdraw in August from public life was accompanied with signals that the monarch was most definitely continuing with her tasks as head of state of the United Kingdom, and of the Commonwealth.
The reassurance was a firm indication that, even at 91, the Queen was not contemplating retirement or abdication in favour of the heir to the throne, her eldest son Prince Charles.
But the events in London this week serve to remind New Zealanders that their head of state resides on the other side of the world and that at some point she too will pass on the royal baton.
When that happens, the changing of the guard at Buckingham Palace is certain to rekindle debate whether having a hereditary monarch as our constitutional figurehead remains fit for purpose in a modern, independent democracy.
For now though, it is appropriate to recognise the remarkably long service of Prince Philip.
From a casual glance, it might seem easy to see the Duke as someone who enjoyed polo, sailing, flying and painting. He did, but he took his royal tasks seriously, and dutifully.
Philip, a Greek prince, had a rocky start to his relationship with the British public. Dismissed in the post-war years as a "German," the starchy palace courtiers regarded him as unsuitable for the young Elizabeth.
The Queen Mother reportedly referred to him as "the Hun". But he persevered and last year became the world's longest serving royal consort. He was always, the Duke of Cambridge has said, "by her side."
He is patron of more than 780 organisations, a number of them in New Zealand. One, the Royal Naval Volunteer Reserve Veteran's Association, reflects his own naval background and the fact that he served with distinction in World War II.
Such are the tangled connections of European royalty that while Philip sailed on Royal Navy ships, two of his brothers-in-law fought for the Germans.
He made 14 visits to New Zealand, 10 of them with his wife. His chief legacy here is through the Duke of Edinburgh's Hillary Award, which encourages young New Zealanders to take part in activities which help build their character.
He has come to be known for injudicious comments, and his quips created the impression of a colonial ruler unaware that the map of the world had changed colour. But he recognised his politically incorrect reputation, once remarking that he had practised the science of putting his foot in his mouth for many years.
Philip has a seldom seen sensitive side. When Princess Diana died, the Queen and the Duke helped their grandsons grieve. Philip gave Prince William encouragement and comfort on the day of Diana's funeral.
In reality, the most we know about the Queen's marriage is its enduring character. Its solidity may have help bind the Commonwealth while other institutions frayed. In that, Philip played his part.
The Duke made an observation about his wife in 1997: "You can take it from me the Queen has the quality of tolerance in abundance." The Queen, in a 2012 speech marking 50 years on the throne, called Philip her "constant strength and guide". Without the Duke alongside, the Queen may that find her role becomes a lonely place to be.