Author John le Carré worked for British Intelligence MI5 and MI6 during the 1950s and 1960s and worked in Berlin where the original The Spy Who Came in from the Cold (1965) film is partially set. Le Carré was there when the Berlin Wall was being constructed. Le Carré drew on this real life experience when he wrote the novel of 'The Spy Who Came in from the Cold'. The novel is set about a year after the Berlin Wall was built.
Author Graham Greene said of the mini-series' source 1963 John le Carré novel of the same name that it was "the best spy story I have ever read".
Reportedly, this television mini-series got green-lit and financed and went into development due to the success of the mini-series of John le Carré's The Night Manager (2016).
The second John le Carré novel to be remade after the original version which was a cinema movie The Spy Who Came in from the Cold (1965). This remake is a TV mini-series. The first John le Carré novel to be remade was the cinema movie Tinker Tailor Soldier Spy (2011) which was a remake of the TV mini-series Tinker Tailor Soldier Spy (1979) which spawned a TV mini-series sequel called Smiley's People (1982). This second remake reverses this order.
The original feature film The Spy Who Came in from the Cold (1965) was the first ever filmed adaptation of a John le Carré story.