The Great Purge is the name of a internal conflict which took place on the Fists of Sol homeworld Nuroq.
As the number of people who questioned Vexar's mission grew Vexar used his power to rally all loyalists into a cleansing campaign.
Armed with the latest in military tech and weaponry they conducted mass arrests and executions, effectively neutralizing all separatists.
Following the Great Purge Vexar had secured his role as the absolute leader of the Fists of Sol. No more separatist movements have sprung up ever since.