The LRA was founded by a woman called Alice Lakwena in Northern Uganda as a movement to fight for the interests of the Acholi people - and was then called the Holy Spirit Movement. Lakwena's cousin, Joseph Kony, took over as leader and re-branded the movement in 1986 as the Lord's Resistance Army.
The 2005 Sudanese peace agreement and the indictment of Kony by the ICC forced the rebels to cross into DRC's Garamba National Park. Offensives have pushed the fighters into north-eastern Congo, the east of the Central African Republic (CAR) and parts of Southern Sudan.
In DRC, LRA militias linked up with the Army for the Liberation of Rwanda (ALIR) and other rebel groups that were battling with forces from the Rally for Congolese Democracy (RCD).
Jospeh Kony's child soldiers
Between December 2007 and April 2010, the group is believed to have killed 1,796 civilians and abducted 2,377 in Congo. The LRA is accused of having abducted large numbers of civilians for training as guerrillas - most victims were children and young adults.
The LRA abducted young girls as sex and labour slaves. Other children, mainly girls, were reported to have been sold, traded, or given as gifts by the LRA to arms dealers in Sudan.
Just a few years ago, the LRA had about 800 combatants. As the result of defection campaigns and operations conducted primarily by the Ugandan military, along with the support by the US, by 2015 it was estimated to have about 200 combatants left.
One LRA senior figure, Dominic Ongwen, was apprehended in 2015 and is awaiting trial at the ICC in the Hague. At least 13,000 members of the LRA have been granted amnesty in Uganda, according to official figures.
Currently operating as rogue small bands for away from the Kivus, "they are certainly the group least connected to the eastern DRC events and have become much more a criminal network than the armed group they used to be", said Christoph Vogel, a political analyst.