It’s official: King Charles III and Queen Camilla have been crowned, well, king and queen. This morning, the royal couple and about 2,000 guests — including first lady Jill Biden, Princes William and Harry, and other members of the royal family — kicked off the coronation festivities with the traditional ceremony. A biggie, considering it’s the first in 70 years. Ahead of the three-day celebration, we spoke to Katie Nicholl, royal correspondent and author of “The New Royals” to learn more about the coronation and its significance. Here’s what she had to say…

Q: Of course, the purpose of the coronation is to crown the next monarch. Why else is it significant?

This is the first coronation that most of us will ever have seen because very few will still be around from the time of Queen Elizabeth II’s coronation. So the rarity of this occasion, the solemnity of this occasion, the symbolism of this occasion, I think is hugely significant. It is the crowning of a new king and queen — and we haven’t had that since George VI and the Queen Mother ... [People around the world are going to] want to witness this moment in history.

Q: In what ways will King Charles III’s coronation feel similar to Queen Elizabeth II’s coronation?

You’re going to have grand processions, an incredible turnout of service members and representatives from the Commonwealth realms and nations ... [Plus] the ceremonial robes, the Coronation Chair, the Stone of Scone — all of these important historical elements of the coronation that have been echoed through the centuries. It’s worth noting that Charles is a man who loves history. He loves music, he loves culture, and he has said himself, he loves ceremony. This is a big part of who he is, the institution from which he comes from. It’s part of his DNA. And of course this is the most important ceremony of his life … So he’ll want all the history and majesty and tradition reflected in this.

Q: And how much will he make his own?

The king is going to invite the people of the nation to swear allegiance to him. That’s a break in tradition because it’s usually just the [hereditary] peers at Westminster Abbey who do that. So you’ll see this is being referred to as the people’s coronation because of that. We are seeing a 1000-year-old ceremony being tweaked for the modern day ... We’ve also got the king reusing certain robes that have been worn historically in previous coronations as part of his drive for a more sustainable reign.

Q: So it’ll reflect the type of king he wants to be?

He’s our green king. He was the one who was warning us about climate change years before anyone was prepared to take him seriously. And so sustainability seems to be very much at the heart of this, from the reusing of robes to Camilla choosing to wear a crown — Queen Mary’s Crown — rather than having one commissioned for this occasion. I also think it’s the sign of a king who’s mindful of Britain being in the midst of a cost-of-living crisis, hence the smaller ceremony and the scaled back security operation ... [all of which is the monarchy] keeping with the public mood because that’s absolutely fundamental to its success and its longevity.

Q: Speaking of longevity, data has shown that support for the monarchy has been slipping. Will that have any impact on the coronation?

I think it’s going to be very interesting to see how many switch on to watch the service, how many switch off during the service, and how many stick with the programming throughout the day and weekend. We saw record viewing figures on the BBC for the Queen’s funeral. I suspect we’re not going to see anything like that number for the King’s coronation ... Charles really has his work cut out in terms of proving why we need a monarchy in modern Britain, why it’s relevant, and how it can serve its people — particularly its young people.