In September 2018, four months after her wedding to Prince Harry, I watched the Duchess of Sussex speak at an engagement in central London.

I’ve seen many royal engagements since I started this job, but this one was different.

We were standing in a marquee in the grounds of Kensington Palace - where, at that time, Harry and Meghan were still living.

The smell of cooking filled the air and there was excited chatter among the crowd.

But this crowd was also different.

It was made up of a group of women, from different faiths and different backgrounds, who all lived in the shadow of Grenfell Tower.

The fire which destroyed that building in West London and cost so many lives had happened the previous year.

In this marquee on that September afternoon, Meghan led the way. Harry took a back seat.

Meghan helped prepare some of the dishes at the kitchen. Credit: ITV News

This was her project.

The Duchess was launching a cookbook, Together.

Inside were recipes, each written by the women of the Hubb Community Kitchen at the Al Mannar Mosque near Grenfell.

The kitchen was the one place where these women could come together and cook, talk and forget everything that had happened around them.

But it didn’t have enough money to open for more than a couple of mornings a week.

Meghan met the women, she saw the problem, identified a solution, made the cookbook happen and then used her fame and royal connections to sell it and raise a lot of money.

The kitchen is now open all week.

And as Meghan stood up and spoke - eloquently and fluently without notes - I thought what a powerful force this woman was going to be as a member of the Royal Family.

Tomorrow, on April 1, they start their new independent life. Credit: PA

Fast forward 18 months, and today that same Meghan and Harry are spending their final day as ‘working’ members of the Royal Family, living in Los Angeles and planning to visit the UK very infrequently.

Tomorrow, on April 1, they start their new independent life.

So where did it all go wrong?

Some royal insiders will tell you that Harry and Meghan could not be satisfied.

They just wanted more and more, they claim.

One spoke of how the Sussexes were given their own home at Frogmore, their own Household separate from William and Kate, their own staff, a new hand-picked Communications Secretary, a new Private Secretary, their own offices at Buckingham Palace, more money for the work they wanted to do and their own charitable Foundation to create projects which meant so much to the couple.

Another described them like children after Christmas who, despite getting a pile of expensive presents, were still asking for more.

Some royal insiders will tell you that Harry and Meghan could not be satisfied. Credit: PA

But those close to Harry and Meghan tell a different story.

They describe a couple who felt unsupported and cut adrift by the rest of the Family.

Meghan was never really made to feel welcome, they claim.

And on the issue that most angered Harry - the treatment of him and his wife at the hands of the British tabloid press - the institution just didn’t give them the support, in public and in private, that they passionately believed they deserved.

There are also accusations of racism, misogyny, and anti-Americanism that have been much discussed.

I’ve recently spoke to someone who has a partner of a different ethnicity and they describe how that they started spotting acts of racism, however large or small, which - before their marriage - they would have missed.

So when Tom Bradby spoke to Harry and Meghan on their Africa Tour in October 2019, it was clear all was not well.

Harry admitted to difficulties in his relationship with his brother and an on-going battle with his mental health.

Meghan said she hadn’t been supported and was fighting an unfair fight with the media.

Tom Bradby told me recently that, after he’d completed those interviews, he concluded that the Sussexes had already decided to leave.

Was it the press’ fault?

Was the rest of the Royal Family and the stuffy institution of Monarchy to blame?

Or were Harry and Meghan too demanding, too self-centred, too difficult?

It's been 1 year and 10 months since their wedding day. Credit: PA

Whatever, the couple decide to do now, they will make a huge success of it.

Put aside the rows about who pays for their security, why they left Canada, and the wisdom of signing up with a big Hollywood PR agency.

The Duke and Duchess are both talented, committed, focused and have huge reserves of energy.

They are also one of the most famous couples in the world and will have offers coming at them from every conceivable business and charitable organisation.

And in any event, who would wish Harry and Meghan to stick with a royal role in the UK in which they were clearly very unhappy for the next 30 or 40 years?

If I look back on the last couple of years, it was obvious that a collision was heading our way.

I just couldn’t tell if it was going to be a collision between the Sussexes and the rest of Harry’s Family - or a collision between the Sussexes and the press.

In truth, it ending up being a bit of both.

I’m just surprised by the speed with which the crash happened.

Because today, 31 March 2020, just 1 year and 10 months after that beautiful wedding at Windsor Castle, it really is all over for the Sussexes and the Royal Family.