An estimated 160,000 people were detained during the insurgency
A compensation claim against the British government brought by veterans of Kenya's independence struggle has been lodged at the High Court.
Three men and two women have launched the case over alleged human rights abuses in the 1950s and 1960s.
Thousands of people were rounded up and forced into camps by the British during what was known as the Mau Mau uprising.
The UK says the claim is not valid because of the amount of time since the abuses were alleged to have happened.
The five Kenyans - aged in their 70s and 80s - are the lead claimants in the reparations case.
'Beaten and castrated'
They want the UK government to acknowledge responsibility for atrocities committed by local guards in camps administered by the British in the pre-independence era.
Their lawyer, Martyn Day, said he believed his clients had "a good chance of success".
He added that the British government of the time had given "a blank cheque" to camp guards in their attempts to force people to abandon the resistance movement.
Mr Day told a news conference: "We want the British government to say what we did was so wrong back in the 1950s.
"What did we do in the period just after the Second World War, how many atrocities were we responsible for in that terrible period?"
The government has indicated that the claim is invalid because of the time that has passed and that any liability rested with the Kenyan authorities after independence in 1963.
Historians say the Mau Mau movement helped Kenya achieve independence.
But their actions have also been blamed for crimes against white farmers and bloody clashes with British forces throughout the 1950s.
The armed movement began in central Kenya during the with the aim of getting back land seized by British colonial authorities.
Veterans of the war say they suffered barbaric treatment, including torture, as the British suppressed the rebellion.
The Kenya Human Rights Commission has said 90,000 Kenyans were executed, tortured or maimed during the crackdown, and 160,000 were detained in appalling conditions.
Ndiku Mutua, one of the five, said: "I live with the physical and mental scars of what happened to me.
"Not a day goes by when I do not think of these terrible events. At last I can tell my story and at last I can hope for justice from the British courts."
Mr Mutua said that in 1954 he was arrested, severely beaten and castrated with pliers, at Lukenya detention centre.
Another claimant, Paulo Nzili, also said he was castrated. Wambugu Wa Nyingi said he was tied upside down by the feet and beaten.
Jane Muthoni Mara and Susan Ngondi said they were sexually assaulted.