Prosecutors say Thomas Lubanga Dyilo commandeered children to fight for the armed wing of his Union of Congolese Patriots (UPC) during the wars that ravaged the Democratic Republic of Congo (DRC). There were more than 30,000 children associated with his militia at the height of the conflict, some as young as 10 years old, the prosecution said.
If the judges approve the charges following Thursday's confirmation hearing Lubanga will be the first suspect to appear before an international court solely on charges of enlisting child soldiers.
The hearing is also important for the ICC which can now finally get down to the business of trying a suspect after recently running into trouble with one of its other investigations into Uganda, where rebel leaders have insisted the ICC arrest warrants against them are withdrawn before they will sign any peace deal.
Lubanga, the ICC's first suspect in custody, has been named in connection with a long series of human rights abuses in Ituri province, where fighting over gold mines and other resources has claimed more than 60,000 lives since 1999, according to humanitarian groups. He has denied all accusations against him.
Child soldiers are said to make up over 40 percent of some armed groups in the DRC with both boys and girls being recruited. The children are often used as sex slaves by commanders or adult fighters.
Former DRC child soldiers interviewed by human rights groups tell horrific tales of being abused, beaten and even forced to kill their own families.
Amnesty says that in 2003 Lubanga ordered all families living on his territory to contribute either money or a cow or a child to his war effort.
The former militia leader was arrested in Kinshasa in March 2005 and transferred a year later to the ICC, the world's first permanent war crimes court, in effect since July 2002. The DRC had asked the ICC to investigate events in Ituri in April 2004.
Lubanga's case represents almost two years of intense on-the-ground investigation work by the office of ICC prosecutor Luis Moreno Ocampo, with scores of missions to the DRC.
Thursday will mark the start of his confirmation hearing, scheduled to take at least 12 days spread out over a period of a month. During the sessions, the prosecutors will present the charges against him and his defence will have the opportunity to contest them. Finally it will be up to the judges to determine whether there is enough evidence to support the charges and proceed to trial.
Prosecutors will present an overview of the evidence against Lubanga, including written testimony from six former child soldiers and one court witness.
The defence will then present evidence to contest the charges. The judges will also hear submissions from lawyers representing victims from the DRC.
The hearing is scheduled to close on November 28. The panel of three judges, presided by French judge Claude Jorda who was formerly on the bench of the International Criminal Tribunal for the former Yugoslavia, will then have 60 days to decide if there is enough evidence to warrant a trial.
Although there was much praise for the arrest and transfer of Lubanga, human rights advocates have expressed regret that he was only charged with using child soldiers, claiming that he is also guilty of other crimes including gang rapes, summary executions and cannibalism.

Copyright AFP (Agence France-Presse), 2006