Jean-Pierre Bemba's troops are accused of rape, murder and pillaging
Congolese ex-Vice-President Jean-Pierre Bemba will face five counts of war crimes, the International Criminal Court has ruled.
The charges relate to the actions of his troops in the neighbouring Central African Republic in 2002 and 2003.
But his lawyers are appealing, saying the militia was not under his command once they had crossed the border.
Mr Bemba led a rebel movement during DR Congo's long civil war but became vice-president under a peace deal.
He is the most high-profile of four Congolese warlords facing trial at the ICC.
A pre-trial panel of judges "found that there is sufficient evidence to establish substantial grounds to believe that Jean-Pierre Bemba Gombo is criminally responsible" for murders, rapes and pillaging, said a statement from the ICC.
He is to face trial on three counts of war crimes and two of crimes against humanity.
Son of famous businessman
Former assistant to Mobutu Sese Seko
1998: Helped by Uganda to former MLC rebel group
2003: Becomes vice-president under peace deal
2006: Loses run-off election to President Joseph Kabila but gets most votes in western DR Congo
2007: Flees after clashes in Kinshasa
Fighters from his Movement for the Liberation of Congo were accused of committing atrocities when they intervened in the conflict in CAR.
At a pre-trial hearing in January, the prosecutor said Mr Bemba "wanted to traumatise and terrorise the civilian population so they would not support the rebels".
"He chose rape as his main method... rapes against mothers in the presence of their children and rapes of children as their parents were forced to watch," the prosecutor said.
The BBC's East Africa correspondent Will Ross says there is no doubt that some of Mr Bemba's troops were responsible for murder, rape and pillaging.
The ICC prosecutors will try to establish a direct line of responsibility between those crimes in the Central African Republic and Mr Bemba himself.
But defence lawyer Aime Kilolo argues that Mr Bemba cannot be held responsible as they were not under his command.
"The most important thing now to do is that for us we submit the case to the appeal and the judge is going now to decide between Mr Jean-Pierre Bemba and the former President Ange-Felix Patasse of the Central African Republic, who was really the commander of the troops," he told the BBC's Network Africa programme.
Human rights groups will welcome the trial as an effort to help end impunity, our correspondent says.
But the ICC does have its critics who accuse it of being selective in its application of justice and wonder why all the current cases are against Africans, he says.
Mr Bemba, 46, was arrested in Belgium last May and extradited to The Hague in July.
One of his defence lawyers has suggested that the charges may be politically motivated, to remove Mr Bemba from future elections in the Democratic Republic of Congo.
He lost a landmark run-off election against President Joseph Kabila in 2006.
He fled the country after being charged with treason after his bodyguards clashed with the army in 2007.