Great Purge

The Great Purge was Nova Magnus's attempt to remove all undesirable elements and information from society.

Fiction

The AllSpark Almanac

Nova Magnus' Protectobots attempt to purge Cybertron was opposed by Devron, founder of the Destrons. Though the Destrons won the war, many Cybertronian records were forever lost. The AllSpark Almanac II

TransTech

When Vector Prime was confronted by Axiom Nexus News reporter Rook, who correctly suspected that Vector Prime was putting on an act of being a normal senile old 'bot, Vector Prime spouted the deflection that Zeemon Magnus's goons were about and therefore he needed to protect what he knew about the Great Purge. Ask Vector Prime, 2015/06/05