Two Iraqi civilians have become the first to claim damages in person at the High Court in London for alleged unlawful detention and mistreatment by UK armed forces.
Previous similar cases arising out of the Iraq war and its aftermath have been dealt with on the basis of written statements and submissions made by lawyers.
Abd Al-Waheed and Kamil Najim Alseran are the first to come before an English judge to give evidence in person, say their lawyers.
On the first day of a five-week hearing, Mr Al-Waheed told the court that he was "truly terrified" after being arrested by British troops and kicked and beaten with rifle butts before being taken away for interrogation.
He is continuing to give evidence before Mr Justice Leggatt.
The Ministry of Defence is denying allegations that the men were treated unlawfully.
The two cases are lead cases, with more than 600 similar claims currently in the pipeline from the period 2003-2009.
The Ministry of Defence (MoD) has already settled hundreds of other claims in what has become known as the Iraqi litigation.
A hurdle the latest claims have to overcome is a Supreme Court ruling in May. The MoD argues the ruling upholds a three-year limitation period under Iraqi law which prevents the cases going ahead in England.
Richard Hermer QC, appearing for both men, opened the hearing by saying the fact that the men's claims arose out of the activities of the British Army in military operations to promote the stability and security of Iraq was not a reason to deny them redress.
In Mr Al-Waheed's case, there were "grave allegations" of unlawful detention and mistreatment which, if proved, "amounted to torture" at the hands of British troops, said the QC.
He was "an innocent civilian" arrested after midnight on the night of February 11-12 2007 in Basra in southern Iraq after soldiers raided his wife's family home searching for an insurgent IED operator.
His experiences, including beatings, interrogations and being held in solitary confinement for 13 days, had had a devastating impact on his life, said Mr Hermer.
Mr Alseran's claim of mistreatment was not as severe, but still raised grave allegations of mistreatment, Mr Hermer added.
Giving evidence via an interpreter, Mr Al-Waheed, 53, told the court he was staying with his second wife, Nazhat, at her family's house in the centre of Basra, when British soldiers carried out a raid.
The soldiers threw him forcefully to the floor and he fell face down.
"Then they attacked me viciously and hit me with their rifle butts and kicked me with their boots," he alleged.
"They were brutal.They hit me randomly anywhere they could and everywhere on my body.
"The soldiers were screaming as well. I think they did that to intimidate us, and I was truly terrified.
"This attack continued and shortly afterwards I ceased to feel pain. I went into a state of shock."
Derek Sweeting QC, appearing for the MoD, cross-examined Mr Al-Waheed and suggested that he had changed his account over what had happened at the house and on the journey to Basra Airport where he was interrogated.
The hearing continues tomorrow.