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.

Comic Books

 * Batman has some of the most colorful Rogues Gallery villains in the history of comics, many of whom had careers that ended before his started - and, in some cases and continuities, died before he was even born:
 * Joe Chill, the mugger who killed his parents, and in many cases, Batman's Starter Villain. He does appear in a few stories, mostly Flashbacks, but in most, he's either dead or in prison and clearly not a threat.
 * Amadeus Arkham was the founder of the notorious asylum named after him, with his mother being the first person to be interred within. Driven mad himself when a criminally insane serial killer named "Mad Dog" Hawkins raped and murdered his wife and daughter, Arkham killed his mother and conducted a dark ritual that was rumored to involve cannibalizing the corpses of his family; he attempted to use sorcery and black magic to bind an evil spirit he calls "The Bat" to himself. When Hawkins was finally sent to Arkham Asylum, Amadeus spent months torturing Hawkins to death through what he claimed "treatment", then did the same to other patients in his care, even after being caught and committed to his own asylum. In spirit, his legacy seems to have cursed Arkham itself, turning it into a hotbed of madness.
 * In most continuities, mobster Tony Zucco only appears in flashbacks, but was responsible for killing Dick Greyson's parents, cementing him as one of the most vile and influential crooks in the franchise.
 * In Marvel Comics, there were the Elder Gods. Only two of them (Gaea and Oshtur) did not degenerate into demons and turn on each other, threatening to destroy creation. Gaea spawned Atum - an embodiment of the sun - to combat them, and only Set and  Chthon survived.

Film

 * Philip Lemarchand from the Hellraiser franchise, the French toymaker who invented the Lamont Configuration and consequently, the first known human to deal with the Cenobites. Exactly how evil he was depends on the version; in the Epic Hellraiser comics series, he is an unrepentant mass-murderer, but in Hellraiser Bloodline, he's much less morally reprehensible.

Literature

 * The Lord of the Rings had many. 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. Other examples of note:
 * Anyone who thinks the balrog that Gandalf slew (Durin’s Bane) was terrifying should have seen their king, Gothmog. This fiend was one of Morgoth’s most powerful servants during the First Age, his raw might the entire reason Morgoth appointed him ruler of his kind. Detailing his evil deeds would take far too much time, but suffice to say he was a major figure in many important conflicts during the First Age before he was slain by Ecthelion burning the Fall of Gondolin.
 * As dangerous as Smaug was, he was hardly the mightiest dragon. The original dragons were created by Morgoth during the first age using a combination of dark magic and elemental fire, and his first success among them was Glauron. Called “the Father of Dragons” (implying he might be the progenitor of the entire race) Glauron had no wings, but was a cunning fiend with a hypnotic gaze that could enspell entire armies or drive them mad, when he had reason not to incinerate them with his fiery breath. Another of Morgoth’s chief lieutenants, his most notorious deeds was the destruction of the elven realm of Nargothrond and the spell he cast on Niënor, causing her to lose her memory and causing the tragic events of the Children of Hurin. While he was eventually slain by Turin, he clearly left his mark on Middle Earth.
 * During the War of Wrath, Morgoth created the stronger winged dragons, and the worst among them was Ancalagon the Black, possibly the mightiest dragon who ever lived. To give an example of how powerful he was, Gandalf claimed “not even” Ancalagon’s breath could harm the One Ring, implying that Ancalagon’s destructive power was second only to Sauron. His entry into the War of Wrath nearly turned the tide in Morgoth’s favor, and seeing as his enemies in that conflict were the Valar themselves, it should give you an idea of how deadly he was. His eventual death is what sealed Morgoth’s fate, ensuring his final defeat.
 * While Shelob was little more than a Giant Spider, she was spawned from a godlike entity called Ungoliant, an embodiment of gluttony and greed. Not even the Valar knew where she came from, but most believed she was spawned by the Darkness itself, making her an offspring of Pure Evil. So powerful that she captured and nearly devoured Morgoth (back when he was still called Melkor), she only failed when the balrogs came to their master’s rescue, but even then, not even the aforementioned Gothmog could slay her, and it was after this battle that she spawned many offspring, including Shelob and the evil spiders of Mirkwood. It is not known how (or even whether) she met her end, but many believe she became so greedy, she eventually devoured herself.
 * A more lighthearted example was King Golfimble, mentioned in The Hobbit. An orc chieftain who invaded the Shire in an event called the Battle of the Green Fields, and according to local Shire folklore, he was slain when Bilbo's great-great-granduncle Bandobras "Bullroarer" Took stuck the villain's head clean off with a wooden club. The unfortunate orc's head sailed a hundred yards through the air and fell down a rabbit-hole; which is how the battle was won and  the game of golf invented in the same instant.
 * Also mentioned in The Hobbit, Azog, the orc lord who slew Thrór, Thorin's grandfather. While a version of this character did appear in the movie, it was due to being Spared By Adaptation. In the original stories, Azog led the assault on Moria that would lead to the dwarves abandoning it, leading to Thorin and his companions falling on hard times. He and his not only killed Thrór, they mutilated his body and kept his head for a trophy, Azog also killing Náin before finally being slain himself by Náin's son Dáin. Unfortunately, Azog's own son  Bolg sought revenge and led the orc legions in the terrible Battle of the Five Armies.
 * 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.
 * All the Sith Lords of the ancient Sith Empire(s) in the Star Wars Expanded Universe can be considered predecessors to Emperor Palpatine and Darth Vader from Star Wars, Darth Bane especially.

Video Games

 * The Legend of Zelda: 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.
 * The Vault-Tec Corporation in Fallout. This Mega Corp created the Vaults and in turn, programed them to orchestrate the horrid experiments done on the dwellers within, thus being the ones responsible for most of the evils present in the Bad Future setting. Ironically, however, there's no real evidence they had a Vault of their own to keep them safe during the Great War, and presumably did not survive it.
 * Also, the Enclave, a shadowy government cell that may have helped cause the war to begin with and ruled what was left of America for ten years afterwards. At least the original members are gone, although The Remnants of the Enclave still cause some trouble.

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.
 * Ragnar the Wretched, Amphibia. Little is known about him, but seeing as General Yunan will never let you forget she is the one who defeated him, he must have been one bad amphibian.