Former Congolese rebel leader Bosco Ntaganda has pleaded not guilty to all charges at the start of his war crimes trial at the International Criminal Court (ICC) at The Hague.
The 18 charges include murder, rape and the recruitment of child soldiers.
More than 2,000 victims have been cleared to take part in the trial, including former child soldiers who will be called as witnesses.
Gen Ntaganda fought for different rebel groups as well as the Congolese army
He stood in the dock, with his signature pencil moustache, making his not guilty plea in a barely audible voice, reports the BBC’s Anna Holligan from court.
The start of the trial was a historic moment for international justice and for the Democratic Republic of Congo, in what is the biggest and most complex case in the ICC’s history, our correspondent adds.
The 41-year-old is accused of killing at least 800 civilians during separate attacks on a number of villages between 2002 and 2003.
He is also accused of raping girl soldiers and keeping them as sex slaves.
In 2013, he handed himself in at the US embassy in the Rwandan capital, Kigali.
He had evaded capture for seven years after the ICC first issued warrants for his arrest.
Bosco Ntaganda was part of the Union of Congolese Patriots rebel group, led by Thomas Lubanga who in 2014 became the only person convicted by the ICC.
Gen Ntaganda was one of the leaders of the M23 rebel movement, which had fought government troops until signing a peace deal in 2013.
Eastern DR Congo has suffered two decades of violence linked to ethnic rivalries and competition for the control of the area’s rich mineral resources.
The unrest began when some of the ethnic Hutu militants accused of the 1994 genocide in Rwanda fled into DR Congo.