Even now you have to sometimes pinch yourself for a reminder that it is true; after all those years of continuity, the Queen has gone and we have a new King.
The weeks since Queen Elizabeth’s passing have provided a startling reminder of just how different the job of Prince of Wales is from that of monarch.
King Charles III began with a new prime minister only just in the job, then had to watch her policies explode and her premiership implode in just a few short weeks.
All the living prime ministers have repeatedly stressed how important their audiences with the Queen were during their time in office, partly because they found her a great sounding board and partly because, in all honesty, they were the only political conversations they could have in a week that stood no chance of being leaked.
So what did the new King say in his audiences with Liz Truss, now officially the UK’s shortest serving and arguably (discuss) worst prime minister?
Did he ask her whether her radical economic polices were really the right ones for turbulent economic times, with inflation rampant? Did he suggest caution?
We will never know and neither side will ever say. But the past few weeks have served as a reminder of how important that relationship can be.
So, after so many years of watching him prepare for this role, what kind of monarch will King Charles III really be?
A long time ago, we started trying to paint a rounded picture of our new King. We hope we have put together a programme full of insights from some of those who have known him best.
His tutor at Geelong Grammar in Australia, where he went to finish off his education, told us what a keen sense of history the young Prince Charles had, driven by an instinctive ability to understand the lives of kings and queens from "within".
'He was one of the most receptive pupils I've ever had'
So if he has a keen sense of history, will he be tempted to make his mark by interfering in the political life of the nation more than he should? That is absurd, say his friends.
Of course, it is impossible to consider the life of the new king without due consideration of the catastrophic damage done to his reputation by his divorce from Princess Diana.
'He knows he failed and he carries that sense of failure with him... but he did his best'
Nevertheless, in a number of ways it is fair to say that, on a lot of issues, King Charles has been quite a long way ahead of his time. On matters of faith, for example.
And almost everyone agrees that Charles has had to be resilient, not least as a result of his somewhat brutal education at Gordonstoun.
It did, say fellow pupils, put a bit of steel in his soul.
As King, he will have to respond to national events. But his past track record suggests that he has a knack for rising to the occasion.
'Prince Charles gripped the riots as if they were in his backyard'
And former prime ministers insist that he has what it takes to be a skilful and smart king.
'I think like his mother it goes beyond duty and service'
All of which has left many who have watched his progress for years keenly awaiting the moment of his coronation.
This documentary is designed to be a portrait of the man we think we know - and of what kind of king he will really be. So do watch!
Charles: Our New King is on ITV at 9pm, Wednesday 2nd November