The Imperial Security Bureau (ISB), also referred to as the Imperial Security Office or the Imperial Secret Service, was a law enforcement and intelligence agency of the Galactic Empire that was charged with matters of internal state security and ensuring the loyalty of citizens to the Empire. Aside from that, it happened to be one of the many umbrella organizations under the greater Commission for the Preservation of the New Order (COMPNOR), and was larger than its sister agency Imperial Intelligence. It was led by ISB high command.

The Imperial Security Bureau was formed by Galactic Emperor Palpatine as a secret law enforcement organization, dedicated to rooting out enemies of the New Order and the Galactic Empire and maintaining stability throughout Imperial territories shortly after the proclamation of the New Order. Within fourteen years, the organization grew from a handful of agents into an organization double the size of Imperial Intelligence.

Following the Clone Wars, the agency helped oversee the dismantling of Confederate warships and martial supplies. Concurrent loyalty purges saw vast amounts of Separatist propaganda destroyed, rescinded, and withheld. Only a handful of propaganda posters such as Ansibella Dellu‘s Count Dooku: Words of Truth escaped the purges. When Art Group agents discovered egregious violations of its artistic tenets, agents of the ISB were called in to make troublesome artists disappear.

Five years into the Emperor’s reign, Imperial Intelligence agents found a cache of communications devices on the remote world of Murkhana and referred the case to the ISB, who brought the matter to the Emperor and his Imperial Ruling Council. It was ultimately decided to dispatch Moff Wilhuff Tarkin and Darth Vader to investigate the cache, which was in reality set up by a small rebel cell, despite the ISB hoping to receive full oversight of the investigation from Imperial Intelligence and the Naval Intelligence Agency.

During that same year, the ISB maintained an active operation on the planet Zeffo, a world that was of interest to the Emperor’s Project Auger. Signs posted by the Bureau on Imperial equipment warned residents of a local village that looters of the project would be shot on sight.