His group is suspected of being responsible for the deaths of hundreds of civilians in the gold-rich north-east Ituri region of the Democratic Republic of Congo.
The 51-year-old former warlord, who has been behind bars in The Hague since 2006, was handed a 14-year jail sentence on Tuesday for abducting children as young as 11, using the boys as fighters in his militia.
During the height of his bloody reign, the tall and lanky leader of the Union of Congolese Patriots (UPC) decreed that every family in his zone of control contribute a cow, money, or a child to support the militia.
To swell the ranks of his army, the ICC heard, his militia abducted and conscripted children from homes, schools and football fields.
Trial prosecutors said girls were also kidnapped and used as sex slaves but sexual crimes were not among the ICC's charges against Lubanga.
Born on December 29 1960 in Djuba, in the Ituri district of the north-east Orientale province, he earned a degree in psychology at the University of Kisangani, the provincial capital.
He became an assistant lecturer in management and development in the early 1990s at the university in Bunia, the capital of Ituri, while also engaging in commerce as a trader in sectors from foodstuffs to gold.
SupportA member of the Hema ethnic group, he entered politics in 1999, a time of land conflicts between Hema communities and another tribe, the Lendu, that quickly degenerated into armed conflict and massacres.
Lubanga, charismatic and regarded as a protector by his community, is said to have founded the UPC with support from neighbouring Uganda before allying in 2003 with a Rwandan-backed militia.
At the head of the UPC, he took over major mining concessions in Ituri.
He supervised the recruitment of children in the UPC's military wing, the Patriotic Forces for the Liberation of Congo (FPLC), in 2002/03.
During this time his militia is accused of killing many Lendu civilians, particularly in his stronghold of Bunia, the capital of Ituri.
When a European force, Artemis, was deployed to quell the conflict in June 2003, he fled and reappeared the following year in Kinshasa.
In the capital, he stayed in a luxury hotel while awaiting a promotion to the rank of general in the Congolese army, a promise that had been made to several Ituri militia leaders who had pledged to disarm.
But a resumption of violence in Ituri and the murder of nine UN peacekeepers in February 2005 prompted Lubanga's arrest by Congolese authorities the following month.
'Noble values and beliefs'From prison in Kinshasa, the affluent and influential Lubanga, known for his dapper dress sense, is alleged to have remained in control of the UPC's operations.
He was arrested on an ICC warrant a year later and transferred to The Hague, becoming its first defendant.
Addressing the court in August 2011, the French-speaker highlighted the "noble values and beliefs" imparted on him during his education, insisting that he had always opposed the military enlistment of minors.
The ICC judge ruled otherwise, finding that Lubanga was "guilty of crimes of conscription and enlisting children under the age of 15 and used them to participate in hostilities".
In the legislative poll organised late last year, Lubanga's UPC party won two seats in Orientale province.
"It shows that his party is still alive and that Lubanga himself still has the support of his community," according to a Congolese civil society activist who asked to remain anonymous.
Lubanga's co-accused in the same ICC case is Bosco Ntaganda, a renegade general who was once the FPLC's military leader and is now running a group of mutineers called M23 who are battling government troops in the east. – AFP