Shortly before 9.30am, the disgraced former cabinet minister, who is serving an 18-month sentence for perjury and perverting the course of justice, arrived by van at Standford Hill prison on the Isle of Sheppey in Kent.
As the Conservative MP for Thanet South, he once made regular VIP visits to the prison. After three weeks at Belmarsh Prison in south-east London, the perjurer bid farewell to his new-found friends on a wing nicknamed "Beirut" because of its violent inhabitants.
One convict, Noel "Razor" Smith, told Punch magazine how Aitken had earned inmates' respect because of his loyalty to his former colleague, Michael "Mental Mickey" Howard, despite the prisoners' open hatred for the former home secretary.
A dishevelled figure in regulation jeans and sweatshirt, the 56-year- old once tipped as a future prime minister "looked like a hamstrung lamb surrounded by hungry wolves", said Smith.
"The consensus was that `Tory Boy' was due for some stick," said Smith. But he said he warmed to Aitken after the former MP refused to agree that Mr Howard should be "publicly flogged" for "putting back prisoners' rights 50 years". This, said Smith, "put the word in the right ears" that he was to be left alone.
When Aitken was asked if he had feared rape, Smith said the Old Etonian had replied: "English public school does prepare one for such eventualities."
But he had turned down an offer of a separate wing because he had not wanted to be "cooped up with the sort of people who go on protection".
Whilst insisting that prison had been better than he expected, "despite rules which seemed to have been written by Lewis Carroll", the ex-minister had been disgusted by the food. He had been sure that "Serbs feed Kosovo prisoners better slops than this".
During his time at the jail, Aitken had also won hearts and minds by turning into a "social worker-cum-agony uncle" and helping with letters home. When not screwing nuts on to bolts for 0.1p each, he had been working on Pride and Perjury, a biography of his fall from grace, due for publication this autumn, as well as another tome on his time in jail.
Yesterday, Aitken moved in with a new circle of friends - category D inmates at Standford Hill, which is known as "The Savoy". Aitken has a single cell, will be assigned a "personal officer" and will be expected to take part in group therapy.
The prison has ample sporting facilities as well as television rooms. Within the relatively enlightened regime, inmates are considered low-risk and are treated with a "considerable amount of trust".
Work there is hard. Classes, including writing courses, are provided by Canterbury College tutors.
Aitken was sentenced to 18 months on 8 June after pleading guilty to perjury and perverting the course of justice in a libel trial against The Guardian and Granada TV.Reuse content