Star Wars: What Does ISB Stand For?

The Galactic Empire is a sprawling regime with countless agents operating within it. Thus, it's comprised of multiple divisions that all come with specialized responsibilities to aid in the Empire's maintenance. There's the overall Imperial Military, which sees to the Empire's dominance on the battlefield, the Advanced Science Division dedicated to strengthening the Empire through science, and the all-seeing and decision-making Imperial High Command, to name a few. One that has taken a place of prominence in "Star Wars" media in recent years is often referred to simply by its abbreviated name, the ISB.

The ISB — short for Imperial Security Bureau — first appears in 1977's "Star Wars: Episode IV – A New Hope," though it's now synonymous with the 2014 animated series "Star Wars Rebels." In that series and various other pieces of "Star Wars" canon material, it's explained that the ISB is responsible for a wide range of duties. It enforces Imperial law across the galaxy in secret, snuffs out potential insurgent movements at Emperor Palpatine's (Ian McDiarmid) request, and collaborates with Imperial Intelligence, to name a few of its main tasks.

Naturally, to meet its often nefarious goals, the ISB is populated by some pretty ruthless individuals throughout its history.

Before it falls apart a few short years after the Battle of Endor, the Imperial Security Bureau enlists some particularly dangerous personnel. Under the command of Clone Wars veteran and former Galactic Republic military figurehead Wullf Yularen (Malcolm Sinclair), Agent and later Captain Alexsandr Kallus (David Oyelowo) rises through the ISB ranks as his protégé. The ruthless Imperial does the Empire's bidding, destroying revolutionaries, their movements, and entire planetary populations before targeting the Ghost crew. Surprisingly, this mission eventually leads to him leaving the Empire behind and becoming a spy for the Rebellion.

Meanwhile, another ISB standout has no such desire to turn his back on the Imperial machine. Moff Gideon (Giancarlo Esposito) — the future Imperial warlord, rival of Din Djarin (Pedro Pascal), and wielder of the fabled Darksaber — aids the Galactic Empire greatly during his tenure under the ISB banner. His most infamous act is taking part in the Great Purge of Mandalore, where the Empire sees to the destruction of the Mandalorian homeworld and annihilates its population. He brokers a deal with Bo-Katan Kryze (Katee Sackhoff), exchanging the Darksaber for Mandalore's safety, only to go back on his word and call for an attack on the planet anyway.

Evidently, the ISB isn't an organization to take lightly. It's run by the worst of the worst, and while it may have its defectors, the heinous actions of those who stick with it are unignorable.