Stale of the century! 200-year-old BISCUIT baked in honour of famed conjoined twins known as the 'Biddenden Maids' is set to fetch £150 at auction

• The crunchy bite depicts the charitable sisters from the 1100s
• Mary and Eliza Chulkhurst were known as the Biddenden Maids
• They left land to church so rent could pay for food and drink for poor It is crunch time for owners of an 18th century biscuit immortalising a pair of kind-hearted conjoined twins next week - when the ancient snack goes up for auction.

  The sweet treat is called a Biddenden Cake and is a rectangular hard biscuit moulded with an image of Mary and Eliza Chulkhurst, known as the Biddenden Maids.

  They were born in the village of Biddenden in Kent in 1100 and lived until the age of 34.

  

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  Taking the biscuit: The sweet depiction of the generous twins is being auctioned next week

  Tradition has it that when one of the twins died the other refused to be separated from her twin, saying 'As we came together we will go together', and died six hours later.

  The sisters are reputed to have bequeathed land to the village, known as the Bread and Cheese Lands, the rent from which was used to pay an annual dole of food and drink to the poor at Easter.

  Since at least 1775 the dole included Biddenden Cakes, bearing the effigy of the conjoined maids.

  

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  A depiction of Mary and Eliza Chulkhurst, known as the famous Biddenden Maids

  

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  There are many different depictions of the Biddenden Maids created over the years

  How rare is having conjoined twins?

  Conjoined twins occur once every 200,000 births and develop from the same fertilized egg.

  The developing embryo starts to split into identical twins during the first few weeks after conception but stops before the process is complete. The partially separated egg then develops into a conjoined fetus. 

  Around 50 per cent of conjoined twins arrive stillborn - while 35 per cent survive just one day, according to the University of Maryland Medical Center.

  Girls stand a better chance of surviving than boys, although the reason for this is not clear.

  One of the earliest documented cases of conjoined twins were Mary and Eliza Chulkhurst, who were born in Biddenden in Kent, England in the year 1100, and were joined at the hip.

  When the wealthy sisters died at the age of 34, they left their fortune to the Church of England. In honor of their generosity, it was customary for English citizens to bake little biscuits and cakes in the sisters' images and give them to the poor. The earliest biscuits made are thought to have been marked only Biddenden, like the example being sold at Dominic Winter Auctioneers in South Cerney, Gloucestershire, on January 21, with a guide price of between £100 and £150.

  Later versions of the 8.5cm by 5.3cm biscuit show the names of the twins and their date of birth and age at death.

  Other Biddenden Cakes can be found in the Pitt Rivers Museum in Oxford and the Wellcome Collection in London.

  Auctioneer Chris Albury said: "We've sold quite a few pieces of wedding cake from the Charles and Diana wedding of 1981 for as much as £1,000 and we are no strangers to selling quirky collectables.

  "A couple of years ago we sold an 18th century gingerbread hornbook mould for £3,200, and we've sold a lot of items relating to the celebrated conjoined twins Chang and Eng, but this quite literally takes the biscuit.

  "There was a lot of consultation and debate among the valuation team and while we are more experienced at dating paper items, pictures and antique objects, we were all quite certain that this was antiquarian and possibly pre-Victorian.

  "Certainly, the deceased vendor among whose effects this was recently found was an 18th century specialist, which tended to back up our hunch.

  "The Biddenden lettering seems to conform to these earlier examples too, and commemorative examples of more recent vintage I have now seen pictures of do look more obviously fresh and perhaps a little more appetising.

  "Our specimen seems to have reached a totally stable condition physically and is unlikely to deteriorate further if kept away from heat and damp.

  "That said, anyone thinking of bidding £100 plus to then eat it would be crackers."

  Maids of honour - or just made-up?

  The story of the Biddenden Maids tells that Mary and Eliza Chulkhurst were born around 1100.

  They were said to have had wealthy parents and the twins were joined at the shoulder and hip.

  When Mary died in 1134 Eliza refused to be separated by a surgeon from her and she too perished just six hours later.

  In their will churchwardens were left 20 acres of land to rent, with the money going to pay for food and drink for the poor.

  But there has been doubt cast on the twins and the reality of their titular charity.

  Edward Hasted’s History of Kent described them as a ‘vulgar tradition’ and questioned their existence.