A collection of never-before-seen photographs and letters that give an insight into Agatha Christie's private life have emerged 45 years after her death.
The photographs show the legendary crime writer celebrating her 81st birthday with friends on Dartmoor, Devon, in 1971, five years before her death in 1976.
The 26 autographed letters and cards were written to the author's long-time friend, Elizabeth Callow.
A descendant of Ms Callow has now decided to put the archive up for sale with Chiswick Auctions of West London and it is expected to fetch £3,500.
The letters cover much of Christie's later life when her health started to fail.
In the letters, Christie talks of the 1971 birthday occasion as well about a snowy Christmas at her Devon property, Greenway, and other snippets from her private life.
She does mention her work occasionally, with one letter from October 1970 referring to a shortage of copies of her spy novel 'Passenger to Frankfurt'.
A collection of never-before-seen photographs and letters that give an insight into Agatha Christie's private life have emerged 45 years after her death. The photographs show the legendary crime writer (left) celebrating her 81st birthday on Dartmoor in 1971, five years before her death in 1976
The 26 autographed letters and cards were written to the author's long-time friend, Elizabeth Callow. A descendant of Ms Callow has now decided to put the archive up for sale with Chiswick Auctions of West London and it is expected to fetch £3,500
Christie is seen posing above as her picture is taken during the day out on Dartmoor with her friends to celebrate her birthday
Christie wrote: 'I'd send you Passenger to Frankfurt but I've run out of it - owing to the birthday rush - and Collins are having to bring out a new edition already'.
In early January 1971, she told Miss Callow of the family Christmas she had just enjoyed in Devon.
Upon returning to her main home, Winterbrook House in Wallingford, Oxfordshire, she wrote: 'We have just got back from a nice but hectic and snowy Xmas at Greenway.
'Very cold and frosty outside*Practically everyone had colds including the children, only I escaped. Perhaps germs don't like the elderly.'
She mentioned her 81st birthday in a letter written in September 1971.
She said: 'I had an agreeable birthday in Devon - a picnic, lovely mildly weather on Dartmoor.'
The same letter also highlights her witty sense of humour.
She wrote: 'I hope I've got the right Elizabeth?!! Nowadays when one only relies on one's friends' Christian names - and as one usually communicates by telephone so that you don't really recognise handwriting - difficulties do arise.'
Her health took a turn for the worse later in 1971.
In another letter from October 1971 she wrote about breaking her hip after tripping on a rug.
Writing of the day out, Christie said: 'I had an agreeable birthday in Devon - a picnic, lovely mildly weather on Dartmoor.' The same letter also highlights her witty sense of humour. She wrote: 'I hope I've got the right Elizabeth?!! Nowadays when one only relies on one's friends' Christian names - and as one usually communicates by telephone so that you don't really recognise handwriting - difficulties do arise'
Having a rest: Christie is seen taking a break on a bench during her grand day out on Dartmoor. The writer's health took a turn for the worse later in 1971
She wrote: 'I, as you may have heard, fractured my hip in early July, it had to be operated on... But I get along on sticks quite well. But what an idiotic thing to do - tripped over the corner of a rug.'
She mentions it again in May the following year when she said: 'I was also rather lame and had to use sticks again.
'My surgeon said my hip was perfectly all right - this was what he called an aftermath* Don't bend too much in your market garden and put a hot water bottle to your back at night!'
Christie sold an estimated 300 million books in her lifetime and is the best selling fiction writer of all time.
Her last novel, Postern of Fate, was written in 1973.
She suffered a heart attack and another serious fall in 1974, after which she was unable to write. She died aged 85 in 1976.
Also included in the archive are 14 letters and cards from Christie's archaeologist husband Max Mallowan, mostly covering work related matters - as Elizabeth Callow was also an archaeologist - but including a letter written after Agatha's death, thanking Elizabeth for her kind
