A long time ago in a galaxy far, far away....
Mas Amedda was the bureaucrat who stood at Palpatine's shoulder through the Republic's final years and then helped run the Empire that replaced it. As Vice Chair and Speaker of the Senate under Finis Valorum, he slowed relief for Naboo during the 32 BBY blockade and steered the chancellor into the missteps that led to his ouster. He then pledged himself to Palpatine, who later told him he was secretly the Sith Lord Darth Sidious. In 22 BBY Amedda nudged Jar Jar Binks into proposing the emergency powers that created the Grand Army of the Republic. During the Clone Wars he ran the secret Strategic Advisory Cell, which oversaw the early Death Star project and Orson Krennic's rise. He also managed the Senate floor for Palpatine, pushing the attempted occupation of Mandalore and the bank deregulation and clone funding bills. When the Empire was declared he stayed at Palpatine's side and presided over the burning of fallen Jedi's lightsabers, then served as Grand Vizier and ran the huge Imperial bureaucracy. After Palpatine died at Endor, Amedda was left as a powerless figurehead under Gallius Rax. Once the Empire collapsed at Jakku, he signed its surrender to the New Republic and stayed on as the nominal head of Coruscant's provisional government. History remembers him as a spineless sycophant.
As Vice Chair and Speaker of the Senate, Amedda uses his bureaucratic power to slow relief for blockaded Naboo. Rumors say he is on the Trade Federation's payroll.
During Queen Amidala's appeal to the Senate, Amedda tells Valorum to sustain Lott Dod's objection. The advice helps provoke the Vote of No Confidence that removes Valorum from office.
Amedda keeps his post after Palpatine is elected Supreme Chancellor and swears loyalty to him. Palpatine later reveals that he is Darth Sidious, and Amedda willingly joins his scheme.
Amedda comes up with the Loyalist Committee's "Strength and Unity" propaganda poster. Because it includes his own image, the press accuses him of narcissism.
After the Separatists' droid army is revealed, Amedda talks Jar Jar Binks into proposing emergency powers for Palpatine, which lets the chancellor activate the clone army.
Amedda stands with Palpatine and the Loyalist Committee to watch the clone army deploy after the First Battle of Geonosis.
Palpatine puts Amedda in charge of the Strategic Advisory Cell, the council that oversees the Republic's most secret military projects. One of his recruits is Orson Krennic.
Amedda backs Palpatine's decision to kill the Zillo Beast so it can be studied. The creature breaks loose and rampages across Coruscant.
Amedda and Palpatine show the Cell the captured battle station plans. Amedda coordinates the project's early stages and reluctantly approves Krennic's plan to recruit Galen Erso.
Amedda pushes the Senate to authorize an occupation of Mandalore over Duchess Satine Kryze's objections. The resolution is rescinded once Deputy Minister Jerec's undoctored testimony comes out.
Amedda presides over the Senate sessions on the Trade Federation's blockade of Pantora.
Amedda helps defeat the Separatist peace initiative. He pushes through bank deregulation and Halle Burtoni's bill to buy five million more clones.
Amedda attends Senator Farr's funeral and follows Inspector Tan Divo's investigation, which ends with Lolo Purs arrested for the murders.
Amedda goes with Palpatine to Naboo, where Moralo Eval's bounty hunters try to kidnap the chancellor.
Amedda is at Palpatine's side when the Empire is declared. He is present when Yoda confronts Sidious in the Senate chamber.
Amedda presides over a ceremony outside the burned Jedi Temple in which the lightsabers of fallen Jedi are destroyed.
Rewarded for his loyalty, Amedda becomes Grand Vizier and sits on the Imperial Ruling Council. He runs the Empire's bureaucracy from Coruscant and sometimes Byss.
After Palpatine dies at Endor, Amedda is left as a powerless mouthpiece for the civilian government, controlled by Fleet Admiral Gallius Rax.
After the Battle of Jakku, Amedda signs the Galactic Concordance on Chandrila, surrendering the Empire to the New Republic.
Amedda stays on as the nominal, powerless head of Coruscant's provisional government while the New Republic restores democracy.