Twenty years on, Harry and I felt that it was an appropriate time to open up a bit more about Mother.

We've never done much. We've done plenty of things symbolically, but we've never actually spoken so publicly about her but we felt that this was the right time to do it.

We won't be doing this again.

So we won't speak as openly or publicly about her again because we feel hopefully this film will provide the other side, from her close family and friends, that you might not have heard before - from those who knew her best and from those who want to protect her memory.

We want to remind people of the person that she was: the warmth, the humour and what she was like as a mother which probably hasn't come across before I many other pieces and from other people.

And I think Harry and I feel very strongly that we want to celebrate her life and this is a tribute from her sons to her.

We want her legacy to live on in our work and feel this is an appropriate way of doing that.

To remind, not only the people who knew her, but also you have to remember that it's 20 years ago when she died and there are people who don't even know about her.

There are 20 or 25 year olds who have heard just a little snippet about her who know a little bit about who she was but nothing really very much about her.

So, this is introducing her to a new audience as well. It's been quite cathartic for us doing it.

It was, at first, quite daunting opening up so much to camera but going through this process has been quite a healing process as well, talking.

Actually, it's been wonderfully refreshing bringing out memories, photographs and things of her and being able to share her and talk about her in a way that sometimes is quite difficult.

We want to share the happiness and the warmth that we had with her and what she was like as a person with a wider audience - and so came the documentary.

I hope you enjoy it.