Evidence, such as references to previously published works, indicates that Turing wrote the manuscript at Bletchley Park no earlier than 1942, when he was working on cracking the famous German Enigma code, which provided the Allies with vital information credited with helping shorten the war.

The unassuming 56-page composition book was previously withheld from sales of memorabilia related to the mathematician because the blank pages in the middle section were used by the British mathematician and logician Robin Oliver Gandy (1919-1995) to keep a personal dream journal. The notebook was part of a collection of papers that were bequeathed to Gandy after Turing's death in 1954.

The notebook was originally bought from a Cambridge stationer's shop and is the only extensive autograph manuscript by Turing to survive.