Vladimir Harkonnen

As Dune begins, a longstanding feud exists between the Harkonnens of Giedi Prime and the Atreides of Caladan. The Baron's intent to exterminate the Atreides line seems close to fruition as Duke Leto Atreides is lured to the desert planet Arrakis on the pretense of taking over the valuable melange operation there. The Baron has an agent in the Atreides household: Leto's own physician, the trusted Suk doctor Wellington Yueh. Though Suk Imperial Conditioning supposedly makes the subject incapable of inflicting harm, the Baron's twisted Mentat Piter De Vries notes:

It's assumed that ultimate conditioning cannot be removed without killing the subject. However, as someone once observed, given the right lever, you can move a planet. We found the lever that moved the doctor.

The Baron has taken Yueh's wife Wanna prisoner, threatening her with interminable torture unless Yueh complies with his demands. Harkonnen also distracts Leto's Mentat Thufir Hawat from discovering Yueh by guiding Hawat toward another suspect: Leto's Bene Gesserit concubine Lady Jessica, of whom Hawat is already distrustful. The Atreides are soon attacked by Harkonnen forces (secretly supplemented by the seemingly unstoppable Imperial Sardaukar) as Yueh disables the protective shields around the Atreides palace on Arrakis. As instructed, Yueh takes Leto prisoner; however, desiring to slay the Baron, Yueh provides the captive Leto with a fake tooth filled with poisonous gas as a means of simultaneous assassination and suicide. De Vries kills Yueh but he also dies with Leto in the assassination attempt; however Harkonnen survives. The Baron then manipulates Hawat into his service, by convincing Hawat that Lady Jessica was the traitor and using Hawat's desire for revenge on Lady Jessica and the Emperor as motivation to assist House Harkonnen.

Jessica flees into the desert with her and Leto's son Paul Atreides, and both are presumed dead. Paul's prescience helps him determine the identity of Jessica's father, the "maternal grandfather who cannot be named" — the Baron himself.[22] Over the next two years, Harkonnen learns that his nephews Glossu Rabban and Feyd-Rautha are conspiring against him to usurp his throne; he lets them continue to do so, reasoning that they have to somehow learn to organize a conspiracy. As punishment for a failed assassination attempt against him, Harkonnen forces Feyd to single-handedly slaughter all the female slaves who serve as Feyd's lovers. He explains that Feyd has to learn the price of failure.

The Baron's plan to assure Feyd's power is to install him as ruler of Arrakis after a period of tyrannical misrule by Rabban, making Feyd appear to be the savior of the people. However, a crisis on Arrakis begins when the mysterious Muad'Dib emerges as a leader of the native Fremen tribes, uniting them against the rule of the Harkonnens. Eventually, a series of Fremen victories against Beast Rabban threaten to disrupt the trade of the spice, inciting the Padishah Emperor Shaddam IV to intervene personally, leading several legions of Sardaukar. After the emperor's arrival on Arrakis, both Corrino and Harkonnen are shocked to learn that rather than a native Fremen warlord, their opponent Muad'Dib is the still-living Paul Atreides, and the Emperor's intervention was part of his plan. The Imperial forces fall prey to a surprise attack by the Fremen, who let a sandstorm short out the force field shields of the transport ships, disable them with projectile weapons, and then mount a mass assault using sandworms as siege-breakers. Their enemies are left trapped on the planet, outnumbered by the many tribes and outgunned by the sandworms. The Harkonnens' past ruthlessness further causes the enraged Fremen to give them little to no quarter; over the course of the battle their entire army is exterminated.

The Harkonnen leadership are also all killed in the course of this battle. Rabban dies first, in the early stages of the battle. Baron Harkonnen himself is poisoned with a gom jabbar by Paul's sister Alia Atreides, a four-year-old born as a fully aware Fremen Reverend Mother, who reveals that she is his granddaughter to him just before his death. His remaining heir Feyd-Rautha is killed in ritual combat by Paul Atreides. House Harkonnen as a political entity is left virtually defunct, permanently excluded from galactic power, though Harkonnen blood is technically ascendant, as Imperial House Atreides is composed entirely of Vladimir Harkonnen's descendants.

Alia had been born with her ancestral memories in the womb, a circumstance the Bene Gesserit refer to as Abomination, because in their experience it is inevitable that the individual will become possessed by the personality of one of their ancestors. In Children of Dune, Alia falls victim to this prediction when she shares control of her body with the ego-memory of the Baron Harkonnen, and eventually falls under his power. Alia eventually commits suicide, realizing that Harkonnen's consciousness has surpassed her abilities to contain him.

In the Prelude to Dune prequel series by Brian Herbert and Anderson, it is established that Baron Vladimir Harkonnen is the son and heir of Dmitri Harkonnen and his wife Victoria. Harkonnen's father had been the head of House Harkonnen and ruled the planet Giedi Prime. Trained since youth as a possible successor, Vladimir had been eventually chosen over his half-brother Abulurd (namesake of the original). Unhappy with his brother's doings, Abulurd eventually marries Emmi Rabban and renounces the family name and his rights to the title. Under the name Abulurd Rabban, he reigns as governor of the secondary Harkonnen planet Lankiveil. Abulurd and his wife have two sons: Glossu Rabban (later nicknamed "Beast Rabban" after he murders his own father) and Feyd-Rautha; Vladimir later adopts the boys back into House Harkonnen, and Feyd becomes his designated heir. The Baron's most prominent political rival is Duke Leto Atreides; the Harkonnens and the Atreides have been bitter enemies for millennia, since the Battle of Corrin that ended the Butlerian Jihad. When Emperor Shaddam IV orchestrates a plot to destroy the "Red Duke" Leto, the Baron eagerly lends his aid.

The young Baron Vladimir Harkonnen is described as an exceedingly handsome man, possessing red hair and a near-perfect physique. The Bene Gesserit Reverend Mother Gaius Helen Mohiam is instructed by the Sisterhood to collect his genetic material (through conception) for their breeding program. As the Baron's homosexuality is something of an open secret, Mohiam blackmails him into having sexual relations with her and conceives his child. When that daughter proves genetically undesirable, Mohiam kills her and returns to Harkonnen for a second try; at this point, he drugs and viciously rapes her. She exacts her retribution by infecting him with a rare, incurable disease that later causes his obesity. Mohiam's second child with the Baron is Jessica.[lower-alpha 2] In Dune: House Harkonnen, the deteriorating Baron at first walks with the assistance of a cane, then relies on belt-mounted suspensors to retain mobility. He consults numerous doctors in the expanse of time between the Dune: House Atreides and Dune: House Harkonnen, up to and including his future instrument Dr. Yueh, all of whom are ultimately no help. To conceal this debilitation, he pretends that his obesity is due to intentional overindulgence, lest the Landsraad remove him from power. When he determines that Mohiam inflicted him with the disease, he attempts to coerce her into revealing the cure, but soon discovers that there is none. The Baron, Duke Leto, and Jessica herself are unaware that Jessica is secretly the Baron's daughter or that he has even fathered one. In the year 10,176, the Baron's grandson Paul is born to Leto and Jessica.

In Hunters of Dune (2006), the continuation of the original series by Brian Herbert and Kevin J. Anderson, the Baron is resurrected as a ghola (5,029 years after the death of Alia) by the Lost Tleilaxu Uxtal, acting on orders from the Face Dancer Khrone. Khrone intends to use the Baron ghola to manipulate a ghola of Paul Atreides, named Paolo. Khrone tries various torture techniques for three years to awaken the 12-year-old Baron's genetic memories; these methods fail due to the Baron's sadomasochistic nature. Khrone is successful when he imprisons the Baron in a sensory deprivation tank for a prolonged period; the Baron's memories of his former life return. The reincarnated Baron is soon haunted by the voice of Alia in his mind; the source of this inner Alia is never explained.

Kenneth McMillan plays Vladimir Harkonnen in Dune (1984)

Baron Harkonnen is portrayed by Kenneth McMillan in David Lynch's 1984 film.[24] The obese and disheveled Baron is overtly unstable, and covered in oozing pustules. William Hughes of The A.V. Club deemed McMillan's facial prosthetics "very memorable".[16] Emmet Asher-Perrin of Tor.com wrote that "Lynch's attempt is infamous for really leaning on [the] codified aspects of the Baron, to the point where his sore-ridden appearance has been called out as a likely connection to the AIDS epidemic, which was a prevalent health crisis while the film was in production."[25] Travis Johnson of Flicks.com.au noted that the Lynch film embraced "the archetype of the depraved gay sadist", which would not be acceptable in 2019.[18] Asher-Perrin added, "Lynch also makes a point of connecting the Baron's desire for men to deviancy and violence, deliberately juxtaposing his assault of a young man with a tender love-scene between Duke Leto and Lady Jessica Atreides."[25]

Ian McNeice plays Baron Harkonnen in the Dune miniseries (2000).

Ian McNeice plays the Baron in the 2000 Sci-Fi Channel miniseries Frank Herbert's Dune,[26] and its sequel, 2003's Children of Dune.[27] Asher-Perrin notes that the miniseries played down the negative aspects emphasized by the Lynch film, and writes, "[The Baron's] appearance was not altered to make him seem ill, he never physically attacks anyone, and the miniseries paid more attention to the fact that the Baron was a rapist, his preference for men being incidental."[25] He also praises McNeice as a standout among the cast, writing that he "manages to make the Baron Harkonnen—easily one of the most despicable characters in science fiction literature—every bit as conniving and vicious as he needs to be...and every bit as fascinating. McNeice has a superb sense of how to make the baron mesmerizing to watch no matter how odiously he behaves".[28] Austin Jones of Paste writes, "McNeice commands his role as Baron Harkonnen, capturing the vile indulgence and vanity of a feudal lord".[29]

Stellan Skarsgård plays Baron Harkonnen in the 2021 film Dune and its 2024 sequel Dune: Part Two.

Baron Harkonnen is portrayed by Stellan Skarsgård in the 2021 Denis Villeneuve film Dune and its 2024 sequel Dune: Part Two.[30][31] Skarsgård called the role "small but important",[32] and noted, "I had seven hours in make-up every day because I had to be really fat."[33] Villeneuve said:

As much as I deeply love the book, I felt that the baron was flirting very often with caricature. And I tried to bring him a bit more dimension. That's why I brought in Stellan. Stellan has something in the eyes. You feel that there's someone thinking, thinking, thinking—that has tension and is calculating inside, deep in the eyes. I can testify, it can be quite frightening.[34]