Collection of rare Alan Turing papers to be auctioned by Rare Books Auctions, after Charles Hanson valuation in Southwell

A series of rare and important scientific papers by mathematical genius Alan Turing are set to be auctioned off next week after drawing attention at a Southwell valuation day.

Alan Turing is known as the father of computer science, having pioneered the subject in the mid-20th century, and famously played a pivotal role in breaking Germany’s Enigma code during the second world war while working at Bletchley Park.

The collection of papers, owned by Alan’s life long friend and fellow mathematician Norman Routledge, includes personal letters, and rare documents known as “offprints” — which are copies of academic material produced in very small numbers and distributed within scientific circles, making them incredibly hard to come by.

The value of the entire collection is difficult to estimate, but some items, including a signed copy of Turing’s PhD dissertation from 1938-39, have been valued at between £40,000 and £60,000.

Alan Turing died on June 7, 1954 from suspected accidental cyanide poisoning. Before his death, he was convicted for being a homosexual at a time when it was still illegal, and given hormone treatment — otherwise known as chemical castration — instead of a prison sentence.

He wrote about his experience in an emotional letter to Norman Routledge — an example of their close friendship — which is now housed in The Turing Archive at King’s College Cambridge.

Norman was gifted the materials by Alan’s mother Ethel following his death, and they remained unseen in a Routledge family member’s loft for decades until they were re-discovered, hidden away in a number of old boxes and carrier bags.

Originally considered for shredding, it wasn’t until the papers were brought along to a Routledge family reunion, and Alan Turing’s signature was noticed, that they realised the importance of what they had in their possession.

Norman’s niece, Bridget Pitcher, of Newark, offered to do some research and took the papers along to a valuation day in Southwell with auctioneer Charles Hanson, who then had them reviewed by an expert.

They were then shown to Jim Spencer, founder of Rare Books Auctions, who was amazed at what had been discovered.

He described the collection as “the most important archive I’ve ever handled,” adding “nothing could’ve prepared me for what I was about to find in that carrier bag.”

“These seemingly plain papers — perfectly preserved in the muted colours of their unadorned, academic wrappers — represent the foundations of computer science and modern digital computing.”

Now, they are due to be auctioned off through Rare Books Auctions in Lichfield, next Tuesday (June 17), listed as ‘The Alan Turing Papers: The Collection of Norman Routledge (1928-2013)’.

Bridget plans to attend the auction in person, alongside her husband and other family members, and described being “quite excited” as they had “no idea what to expect.”

“This whole journey has been one of new experiences and excitement,” she said.

“We have never done anything like this before and the wonderful thing is that Jim Spencer is just as excited as we are.

“My uncle was such a special man, he was always interested in the lives of everyone around him and genuinely cared.

She added: “I hope that [his collection] ends up with people who will really appreciate it.”

Charles Hanson, who will oversee the sale, said: "We're thrilled to be handling this remarkable collection of Alan Turing's papers, which offer a unique glimpse into the development of computer science.

“Items of this significance and provenance rarely come to market, making this a truly exceptional opportunity for collectors and institutions.

“I recall taking these papers in at our valuation day in Southwell, and I really wasn’t expecting something this important to come through the door that day — it's a testament to the hidden gems that can be uncovered through our valuation process."

Other items in the collection include a copy of Alan Turing’s ‘On Computable Numbers 1936-37’, which introduced the world to the idea of a universal computing machine; correspondence between Norman and Alan, as well as with novelist E. M. Forster; a handwritten letter from Ethel Turing sent alongside the papers she gifted to Norman; as well as an autobiographical manuscript about Norman’s life.