The International Criminal Court (ICC) has ruled there is enough evidence against a DR Congo militia leader to launch the court's first trial.
Lubanga denies three war crimes charges
Thomas Lubanga, 46, is accused of recruiting child soldiers during DR Congo's brutal 1998-2003 civil war
Prosecutors allege that children as young as 10 were kidnapped and forced to fight in 2002-2003,
The ICC, based in The Hague, was set up in 2002 as the world's first permanent war crimes court.
It was designed to end the need for the various ad hoc war crimes courts which have been established, including the chambers created to deal with war crimes committed in the former Yugoslavia and the genocide in Rwanda.
The US strongly opposed the creation of the ICC, fearing the political prosecution of its soldiers.
Four million people are estimated to have been killed during the conflict in the Democratic Republic of Congo,
Mr Lubanga led the Union of Congolese Patriots (UPC) militia in the north-eastern Ituri district, where fighting continued long after the official end of the five-year war in 2003.
"Lubanga made children train to kill, Lubanga made them kill and Lubanga let the children die... in hostilities," prosecution lawyer Ekkehard Withopf told the court during a hearing in November.
The prosecution says children were snatched as they walked to school and forced to fight for Mr Lubanga's ethnic Hema militia against their Lendu rivals.
The child soldiers were later instructed "to kill all Lendu including men, women and children", a prosecution statement says, based on testimony from six children.
Mr Lubanga denies any wrongdoing. His lawyers say he was trying to end the conflict and is being punished by the international community for refusing to give mining concessions in areas he controlled to foreign firms.
Referring to his enemies, he once told UN peacekeepers: "Those who have committed genocide or massacres have to be punished."
The BBC's Mark Doyle says the conflict in Ituri manifests itself as an ethnic war, but its root cause is the criminal mining of the region's gold and other minerals.
Lobby group Human Rights Watch says some 60,000 civilians have been slaughtered in Ituri province by various militias.
It calls for them all to be investigated, along with government officials from DR Congo and others who may be implicated from neighbouring Rwanda and Uganda.