Vladimir Harkonnen, or known as Baron Harkonnen, is the last Baron of the ancient noble House, House Harkonnen. He is a cunning, intelligent yet cruel and sadistic man. His skills focus on manipulating others, ruling by terror and making his servants compete for his blessing. He is immenssely fat and uses anti-gravity devices to hover. Baron is also known for prefering young men as sexual partners. He is the father of Lady Jessica Atreides, and also a grandfather to Alia and his brother Paul. Other than that his only known relatives are his nephews Rabban and Feyd-Rautha. He encourages a competition between them for the throne of Harkonnen.
In the series, Baron plots a plan to destroy House Atreides with Emperor's help. For this plan he uses a trusted Suk doctor, Yueh, as a lever by kidnapping his wife. Yueh, a doctor of House Atreides, disables Atreides Palace's shield generators and enables combined forces of Harkonnen and Sardaukar to rush in without much resistance. Afterwards he captures his life-long rival Duke Leto Atreides. But with a false tooth given by Yueh, the Duke attempts an assassination which fails to kill the Baron, but instead kills his mentat, Piter de Vries. During the assault Duke's wife Lady Jessica and his son Paul menages to escape. Baron, however is sure of their death in a coriolis storm on open desert.
From this point Baron turns his attention to internal matters. He tries to consider which of his nephews will be best for the throne. He survives an assassination attempt ploted by Feyd-Rautha and his newly converted Atreides mentat, Thufir Hawat. Baron admires Feyd-Rautha's ambition, as well as his physique and intellect. Baron runs gladiatoral games on Geidi Prime to promote Feyd-Rautha as his official heir. He also makes his savage nephew Rabban, the governor of Dune, which is now in a turmoil bacause of uprising tribes of locals, the Fremen. He plans to Rabban to be hated by the people, and send in Feyd-Rautha for him to be seen as a savior to the planet's populace, thus increasing his influence on people. His plans, however do proceed as expected as the uprising becomes far more serious, so he attends to an attack on Arrakis with Padishah Emperor. When Emperor's encampment is attacked by the Fremen, he gets killed by captured Alia with Gom Jabbar, a strong poison sting. So his, and his House's fate is sealed.