With financial support from Kenyan human rights organisations, they launched their case in the High Court in London. The British Government, while admitting the torture, claimed the victims should sue the Kenyan Government instead, since it had inherited the responsibilities of the former colonial administration at independence in 1963.
Lawyers really do use arguments like that. They don't even blush when they do it. But in June of last year the High Court rejected the British Government's defence - whereupon its lawyers shifted their ground and said it was all far too long ago. The few surviving witnesses are too old, and there are no documents. Sorry, we'd love to help, but in the circumstances ...
Last Friday the same High Court judge dismissed that argument, too. There are actually almost too many documents: the publicity surrounding the case led to the discovery that the British Foreign Office has been hiding 8800 files about the Kenya abuses in a country house in Buckinghamshire for the past 50 years.
Those files contain enough evidence to prove the truth of what the claimants say. The British Government will appeal the judge's ruling, probably in the hope of dragging things out until the claimants die (two are in their mid-80s) or become too ill to testify. But it's likely that the lawsuit will be heard next year, and will result in a victory for the claimants.
That would open the floodgates for thousands more claims for compensation from other Kenyan victims of British atrocities. It would also allow many thousands of ageing victims of British violence and cruelty elsewhere during the last years of the empire, especially in Malaysia, in Cyprus, and in Aden (now Yemen), to seek compensation in the British courts for their suffering.
So if these half-century-old injustices can be acknowledged by the courts and at least partly compensated, how about more recent ones? What are the chances that a British or American court will one day offer compensation to innocent Arabs, Afghans and other Muslims who were swept up in the so-called "war on terror" and spent years in confinement without charge or trial, often being beaten or tortured? Very small, unfortunately.
Most crimes go unpunished. It's true in private life, and it's even truer for great states. But gradually, at the edges, the courts are making inroads on this ancient and brutal reality. As in, for example, Kenya itself.
After the post-election violence in Kenya in 2008, in which both the leading parties were implicated, a Commission of Inquiry led by Judge Philip Waki recommended the Kenyan Government set up a special tribunal to prosecute those responsible for the worst crimes.
The National Assembly of Kenya, taking the British Government as its model, refused. But the judge passed his evidence to the International Criminal Court, which opened a case against the senior officials of both parties held to be most responsible.
The Kenya Government did everything it could to stop the case, but it is going ahead in the Hague anyway - and a majority of ordinary Kenyans support the ICC process.
So there is progress, if only slowly.