The UK terror trial of an alleged member of the Islamic State (IS) group's "Beatles" kidnap-and-murder cell begins on Monday.
Aine Davis is accused of belonging to the notorious group of four hostage takers, who grew up and were radicalised in London, something he is understood to deny.
Active in Syria from 2012 to 2015, the four were allegedly involved in abducting more than two dozen journalists and relief workers from the United States and other countries.
The group members were nicknamed the "Beatles" by their captives because of their distinctive British accents.
The hostages - some of whom were released after their governments paid ransoms - were from at least 15 countries, including Denmark, France, Japan, Norway, Spain and the United States.
The Islamic State group tortured and killed its victims, including by beheading, and released videos of the murders for propaganda purposes.
Davis, who is in his late thirties, will go on trial at the Old Bailey criminal court in London.
He faces two formal charges related to providing money for terrorist purposes and one of possessing a firearm for a purpose connected to terrorism.
The trial is expected to take less than two weeks.
Davis was arrested in Turkey in 2015 and sentenced in 2017 to seven and a half years for membership of IS.
He was released in July last year and deported from Turkey the next month. He was re-arrested when he arrived at Britain's Luton airport.
In 2014, his wife Amal El-Wahabi became the first person in Britain to be convicted of funding the Islamic State group after trying to send 20,000 euros - worth $25,000 at the time - to him in Syria.
She was jailed for 28 months and seven days following a trial in which Davis was described as a drug dealer before he went to Syria to fight with IS.
Two of the "Beatles", El Shafee Elsheikh and Alexanda Amon Kotey, have received life sentences in the United States.
Former British national Elsheikh was sentenced last year for the deaths of four US hostages in Syria.
The trial featured emotional testimony from former hostages and was the most significant prosecution of an IS member in the United States.
Ten former European and Syrian hostages testified at Elsheikh's trial, accusing the "Beatles" of months of brutal treatment including beatings, electric shocks, waterboarding and mock executions.
Elsheikh and Kotey were captured by a Kurdish militia in Syria in January 2018 and handed over to US forces in Iraq.
They were flown to the United States in 2020 to face trial. Kotey pleaded guilty in September 2021.
The fourth in the group, executioner Mohammed Emwazi, was killed by a US drone in Syria in November 2015.