Massacre of the CPG

The CPG Massacre was an incident in the 2230s where the Institute killed representatives of settlements intent on forming a 'Commonwealth Provisional Government', or CPG, ending all further attempts to form a regional government.

Prelude
For some time, various settlements attempted to unite together and form a larger regional government for the Commonwealth. For four years, the Institute was also a part of this process, but began to believe that the project was falling apart due to political infighting. At the behest of some divisions, the Director of the Institute chose to abandon the CPG sometime after 2187 and closed off all connections between the Institute and the surface.

Massacre
Father mentions the event as an attempt to create a stable Commonwealth government gone awry. Under the supervision of the Commonwealth Minutemen, multiple settlements sent representatives to a meeting to discuss the terms for the Commonwealth Provisional Government in the 2230s. However, according to Nick Valentine, the meeting was interrupted by the arrival of an Institute synth, who proceeded to attack and kill all of the representatives. Following the deaths of everyone, all negotiations effectively ceased and no further attempts at forming the CPG were made. Within the Institute itself, it is revealed that the cause of the massacre was likely accidental.

Appearances
The CPG Massacre is mentioned only in Fallout 4.