The leader of a Democratic Republic of Congo militia has become the first war crimes suspect to face charges at the International Criminal Court.
Thomas Lubanga's UPC has been battling for control of Ituri's gold
Thomas Lubanga was transferred to ICC custody on Friday from DR Congo.
He appeared before the court, based in the Dutch city of The Hague, to face three charges relating to the use of children in armed groups.
The ICC was set up in 2002 as a permanent court to deal with war crimes and genocide around the world.
"For 100 years an international court was a dream, now it's becoming a reality," said chief prosecutor Luis Moreno-Ocampo.
Mr Lubanga appeared on Monday before judges in a hearing that mainly dealt with administrative issues.
Further charges are being prepared and are expected to be confirmed at the court's next session in June.
He wore a dark suit and speaking in French, he said he was "a politician by profession".
His provisional defence lawyer Jean Flamme said he would be asking for his client to see the file on his case, as he said Mr Lubanga had been held in jail for a year without being told of the charges he was facing.
Mr Lubanga was arrested a year ago after nine Bangladeshi UN peacekeepers were killed in the volatile Ituri area.
His ethnic Hema Union of Congolese Patriots has been battling rivals from the Lendu ethnic group, partly for control of Ituri's large deposits of gold.
CHARGES FACED BY LUBANGA
Enlisting children under the age of 15 into armed groups
Conscripting children under the age of 15 into armed groups
Using children under the age of 15 to participate actively in hostilities
Several teams of ICC investigators have been sent in recent months to Ituri, where more than 50,000 people have died since the inter-ethnic war began in 1999.
The BBC's Robert Walker, who has travelled widely in eastern DR Congo, says Mr Lubanga emerged as one of the most notorious warlords in the civil war of the late 1990s.
Soldiers under his command are accused not just of murder, torture and rape, but also of mutilating their victims, our correspondent says.
In one massacre, human rights groups say, Mr Lubanga's militiamen killed civilians using a sledgehammer.
At different times, the UPC was backed by both Uganda and Rwanda - DR Congo's neighbours, which were closely involved in its conflict.
Some 17,000 UN peacekeepers are in DR Congo, tasked with ensuring that elections scheduled for June go smoothly.
They have been backing up the Congolese army as it conducts raids against the numerous rebel groups based in the east.
'Exception to the rule'
Our correspondent says the challenge for DR Congo and the ICC is to bring to justice the many other warlords who committed crimes during the civil war.
Rape and killings still continue in the east and for now the charges against Mr Lubanga are an exception, and impunity still the norm, he says.
The ICC has also issued its first arrest warrants for the leaders of Uganda's rebel Lord's Resistance Army but they remain at large.
It is also investigating alleged war crimes in Sudan's Darfur region.
The existence of the court is strongly opposed by the United States, which fears its troops could face political prosecutions.