Predecessor Villain

At some point in the backstory, a villain existed who was the forerunner to the current Big Bad- either because they were both part of a direct line of succession, or just because the Big Bad uses similar methods and espouses similar beliefs. The Predecessor Villain may appear in flashbacks, but will usually have no direct role in the story (unless it turns out to be Hijacked By Ganon, from an in-universe standpoint)- usually, though not always, they are a Posthumous Character.

May be used to reinforce a theme of history being cyclic, or just to give the current Big Bad a well of secrets and power to mine. Sometimes, particularly if the current Big Bad is the Evil Counterpart to The Hero, then the Predecessor Villain will be the same to the mentor- and may have been their Arch Enemy at one point.

Compare and contrast Bigger Bad for a somewhat similar idea, except that the Bigger Bad still exists during the story but takes little to no active role in it, rather than having existed in the story's past.

For cases where the Big Bad goes down and is replaced by a Bastard Understudy or underling during a work, see Dragon Ascendant.

Anime and Manga

 * In Naruto,
 * Bibidi, Babidi's father and the creator of Majin Buu in Dragonball Z.
 * Bleach is what happens when the Disc One Final Boss is given such a treatment.
 * Big Bad of Gundam Seed is this to, Big Bad of Gundam Seed Destiny. The two of them were friends, and the former's depression and disgust with the world are what ultimately led to the latter becoming the man he is today. Take out of the equation, and you take out , as all of his actions are rooted in 's Nietzsche Wannabe Omnicidal Maniac philosophy.

Expanded Universe

 * All the Sith Lords of the ancient Sith Empire(s) can be considered predecessors to Emperor Palpatine and Darth Vader from Star Wars, Darth Bane especially.

Literature

 * In The Lord of the Rings, Sauron is the Dark Lord and God of Evil, but the job was originally held by Morgoth, his old master, who was worse on a grander scale.
 * In Harry Potter, Salazar Slytherin and Gellert Grindelwald were both predecessors to Lord Voldemort, but neither were nearly as bad as him. Slytherin (a friend of Gryffindor) is implied to have undergone Historical Villain Upgrade in-universe; Grindelwald was imprisoned and refused to help Voldemort when Voldemort called on him (Voldemort ultimately got what he wanted anyway, but Grindelwald still didn't help him). Not to mention that it's likely he threw the decisive duel with Dumbledore.
 * From the Dragon Crown War series, the actions of a Sorcerous Overlord named Kirun play a large role in shaping the settings' history, but the Big Bad is his ex-Bastard Understudy, Chytrine.
 * In The Dresden Files novel "Dead Beat", the necromancer Kemmler is the predecessor to a whole flock of lesser necromancers, most notably Grevane, Corpsetaker, and Cowl.
 * In Dragonlance, Fistandantilus is the predecessor or Raistlin, made more complicated when Raistlin travels back in time, kills Fistandantilus, steals his secrets, and usurps his place in the timeline.
 * Baron Ether in Soon I Will Be Invincible is an retired supervillain now living under house arrest. Dr. Impossible, one of the book's two viewpoint characters sees him as a mentor and visits him twice for advice while trying to get his Evil Plan set up.
 * The Wizard-King Xhum Y'zir is the forerunner of many of the villains from the Psalms of Isaak series, some of whom worship him as a god while others, like Sethbert just use his leftover weapons. While it's possible he's still alive and secretly the Big Bad, nothing has been confirmed.
 * Soundscape has Apocesis as the very first Eldritch Abomination to have ever existed, responsible for desolating Earth and forcing the humans to repopulate into another dimension. At least, that's what the rumors say.

Video Games

 * Skyward Sword The Big Bad Demise is not only the forerunner to the series' main Big Bad Ganon, but
 * Knights of the Old Republic has Mandalore and Revan.
 * Its sequel has the role thrown onto Malak.
 * Don't forget Exar Kun.
 * In Cave Story, Halda, Anacpohne, and Miakid preceded The Doctor in the line of Demon Crown-bearers. Miakid is particularly notable,
 * Professor Gerald Robotnik, who was the Big Bad of Sonic Adventure 2 and grandfather to Dr. Ivo "Eggman" Robotnik. Eggman looked up to him as his role model and was the reason Eggman went into robotics in the first place, considering Gerald a more competent roboticist than himself. While already dead for 50 years by the start of the game, his plan to posthumously kill off humanity was so twisted and so difficult to stop that Eggman, in a major case of Even Evil Has Standards, formed an Enemy Mine with Sonic in order to avert the catastrophe. Eggman has since seen him as a Broken Pedestal.

Western Animation

 * Fire Lord Sozin was the one who began the war of conquest that dominates Avatar: The Last Airbender, but by the time the series begins, he's long dead of old age, and the Fire Nation is ruled by his grandson, Fire Lord Ozai.
 * Also Sozin's son, Azulon. We don't know much about his actions during the war, but he was nasty enough to order Ozai to  when Ozai ticked him off.
 * Both Big Bads of My Little Pony Friendship Is Magic, Nightmare Moon and Discord, were originally the enemies of Princess Celestia, Twilight Sparkle's mentor. In the latter case, Discord was also an enemy of Luna, who became Nightmare Moon.
 * In The Legend of Korra, Yakone is this to both Amon and Tarrlok.