Here's how Princes Harry and William are marking the anniversary of their mother's death

Twenty-one years on.

Today marks 21 years since Princess Diana died tragically in a car crash in Paris.

While last year's 20 year anniversary pulled out all the stops, with exhibitions and documentaries created in her name - not to mention the opening of the White Garden in Diana's old Kensington Palace home, this year's memorials are more private.

Prince William and Prince Harry are thought to be mourning Princess Diana's death privately, with neither royal booked in for any official engagements all day.

'There is no official engagement planned and we don’t have a comment on what the family would be doing,' a Kensington Palace spokesperson told Express.co.uk.

'I was very touched by it, but none of it sank in,' Prince William explained of the tributes that were left for his mother 21 years ago. 'All I cared about was, I'd lost my mother, and I didn't want to be where I was. When we go out and do things like that, in order not to completely and utterly break down, we have to put on a bit of a game face. And you have to be quite strong about it because otherwise you're a walking mess.'

Prince Harry agreed, 'Looking back now, probably the last thing I wanted to do was read what other people were saying about my mother. Yes, it was amazing. It was incredibly moving to know, but at that point, I wasn't there. I was still in shock.'

Last year, her two sons had a statue created and erected in their mother's memory.

‘It has been 20 years since our mother’s death and the time is right to recognise her positive impact in the UK and around the world with a permanent statue,’ the brothers explained in 2017. ‘Our mother touched so many lives. We hope the statue will help all those who visit Kensington Palace to reflect on her life and her legacy.’