Agatha Christie: How donations from The Mousetrap shaped the arts
Seventy years ago this month, a theatrical phenomenon and a nine-year-old boy changed the face of Welsh arts.
On 25 November 1952, Agatha Christie's The Mousetrap opened on the West End.
She gifted the rights to the play to her Welsh grandson, Mathew Prichard, as a ninth birthday present.
Investing the tens of millions of pounds it has grossed in the past seven decades of over 28,500 shows, Mr Prichard set up the Colwinston Trust.
rust has gone on to support some of Wales' most famous venues, including the Wales Millennium Centre, The Welsh National Opera, and Cardiff's Chapter Arts Centre.
Set in a bleak guesthouse cut off by a snow storm, The Mousetrap is regarded as one of the finest exponents of the so-called closed room detective genre.
Agatha Christie bet her agent it would last "eight months… 14 tops".
Yet since 1995, its legacy has supported theatrical enterprises from north to south Wales, with grants ranging from £5,000 to £1m. 
Mr Prichard said: "To be honest with you, I don't remember an awful lot about the day I received the documents, at nine. I think I'd have rather have had a Spitfire Airfix model."
However, as he grew into his teens he began to realise the enormity of the gift he had been given.
He said: "My grandmother joked with me that if she'd have known how long The Mousetrap would run then she'd have left it to the cat's home or something, but she really knew what she'd done."
Mr Prichard said his grandmother accepted him "warts 'n' all", while his parents "couldn't see past my failings". 
He said: "She was always willing to see the best in me, and despite all the claims that she must have had on her time back then, she never let it show to me. 
"She made me feel like I was the only person who was important to her."
Source: The Home of Agatha Christie
After a career in publishing, in the 1990s - as The Mousetrap clocked up its 20,000th West End showing - Mathew turned his attention to divesting his grandmother's legacy into his favourite causes where he grew up in Vale of Glamorgan.
"I put the royalties into the Colwinston Trust, named after the village where I've grown up," he said.
"Some have questioned my Welshness - going to Eton and Oxford. 
"But I always support Wales in the rugby, and I've put my grandmother's money where my mouth is, back here at home."
He said none of the trust's work would have been possible without the help of his long-suffering personal assistant Amanda McMurray.
"I'm an impulsive investor, letting my heart lead me to what I'm interested in rather than going in with my business head," he said.
"But Amanda is always there with the spreadsheets, advising me on what will be the shrewdest opportunities."
Mr Prichard said some of the projects he had invested in "have tanked", but he does not regret a single one.
"We've granted funds to a young cricketer from Barbados, and whilst you probably won't have heard of him, his success gives me every bit as much pleasure as the headlines like the Wales Millennium Centre," he said.
As for his grandmother, Mr Prichard said some things are just meant to be.
Agatha Christie spent both world wars serving as a dispenser for pharmacies and met her second husband on an archaeological dig.
He said: "Agatha had always had a prodigious imagination, spending her childhood largely on her own.
"But without the knowledge of drugs and pathology which life put in her way, who's to say that she'd have developed into quite the same gripping author."