The depths of the sea have been plumbed and surveyed, leaving no place for the sea monsters to dwell. Every river and every forest used to be believed to have a spirit living in it: but they have all been expelled by our advancing science and clonking civilization. Even the human soul has been given notice to vacate! Already we’ve had several pink slips delivered by psychology and neuroscience; and now the bailiff of AI is knocking sternly at the door with a warrant to take possession.
Deep Utopia
Nick Bostrom
Probably not super helpful/what you’re looking for, but one broad category of groups who go from ‘doing violence’ to ‘doing much less or no violence’ (often within a short space of time) are resistance organisations that successfully manage the transition, usually after achieving some level of progress. The ANC in South Africa seems like a good example. Sinn Féin in Ireland (established as the political wing of the IRA) is another.