Bane's Militia

Bane's Militia is a group of former Peña Duro inmates turned mercenaries, who were assembled to fight under the command of Bane. The militia's second-in-command is Bird.

Arkham Origins Incident
Bane's Militia appeared during the Christmas Eve Incident, and caused various problems in Gotham City. By the end of the incident or soon afterwards, the militia was disbanded, since Bane and Bird were both sent to Blackgate Prison, and many of its members had been killed or arrested.

Arkham Origins Multiplayer Incident
Bane's Militia later fought in a series of gang wars against The Joker and his henchmen.

Trivia

 * Conversations from Batman: Arkham Knight confirmed that some members of the Arkham Knight's Militia were also involved in Bane's Militia during Batman: Arkham Origins.