warlord
The independent leader of a private military detachment which uses civil dominion over the residents of a region, usually by military force.
Example:
Bosnia, Serbia, and several similar countries used to be ruled by warlord factions in the 1990s until NATO and expeditionary forces brought about factional demise.
Bosnia, Serbia, and several similar countries used to be ruled by warlord factions in the 1990s until NATO and expeditionary forces brought about factional demise.