Naka Ward
The Naka Ward of Nagoya is a location in Area Eleven that was recently the center of a major military incident and cover-up. The public is broadly aware that an insurgent group seized a Britannian military transport leading to military response within Naka, but isn't aware of the full scope of what happened. This incident is referred to in common conversation as The Tragedy of Naka. Serious casualties were sustained within Naka, depopulating and damaging it significantly. Prior to the Tragedy, Naka was recovering from the war, and had been on the cusp of returning to something resembling a pre-war standard of living.
Though the majority of the victims were Elevens, a proportionately high number of Britannian casualties have been used to sell the illusion that the Tragedy was more of a disaster than any kind of military action, and certain pro-reconciliation parties have pushed it as an occasion for increased unity. Battlefield tourism by Britannian civilians has, however, undermined this effort even among those that would otherwise be receptive to it.
Within the Britannian military, it is understood that the military transport contained a chemical weapon, and that the insurgents also claimed a train shipment of Sutherlands that they used to engage Prince Clovis's forces. At that point a purge of the Ward was ordered by the Prince, and later rescinded for reasons believed to be connected to Clovis's death. The precise details have been obfuscated by a combination of Clovis's former inner circle suffering some form of collective amnesia, and deliberate cover-up efforts. A considerable portion of Clovis's total personnel roster was recalled to the capitol pending inquiry, and his officers are tacitly understood to be under arrest pending the same.
Within the Black Knights, the Purge is understood to be an inciting reason for their formation. The resistance cell that preceded the Black Knights as a formal organization was the group that seized the military transport and later engaged Britannian forces in stolen Sutherlands. The actual purge was however an unexpected twist of events even to them; prior to that point Clovis was a lukewarm antagonist with equally milquetoast advisors.
Although there are direct eyewitness survivors, practically all of those who would be willing to tell the truth are themselves insurgents already.