Moff was the political rank held by the governors of each sector in the Galactic Empire. A collective body called the Council of Moffs was created by Galactic Emperor Sheev Palpatine.
More powerful than a regular Moff due to his favor with Emperor Sheev Palpatine, Moff Wilhuff Tarkin held great influence in the Empire.
In the fifth year of Emperor Sheev Palpatine's reign, there was a fixed number of twenty Moffs, who answered to the Imperial Ruling Council. That same year, the senior rank of Grand Moff was created and awarded to Wilhuff Tarkin. As a symbol of their charge, Moffs wore a rank insignia plaque bearing ten colored squares: five blue over three red and two gold or twelve squares: six blue over three red and three gold. Moffs could use four code cylinders, with two on each pocket.
Moffs were in command of their sector's Sector Group, a formation that contained assets from the Imperial Military and intelligence. Moffs could be appointed by the Emperor or an advisor, but were obligated to report to both. A Grand Moff, overseer of an oversector, could override any Moff. In the aftermath of the Battle of Endor, Moff Valco Pandion proclaimed himself a Grand Moff and tried to assemble his own fleet. Further into the New Republic Era, Gideon led a sizeable Imperial remnant under his title of moff.
In Star Wars: Episode VI Return of the Jedi, Moff Jerjerrod wore the rank plaque of a commander due to a costuming error. The rank badge specific to Moffs was first depicted in an illustration by Joe Corroney for Tarkin Revealed, an article by Michael Kogge that was published in Star Wars Insider 153.