Sworn to protect England from the supernatural, Sir Integra of the Hellsing Organization fights alongside her protector, the immortal vampire Alucard. A flashback reveals the act of treachery that awakened Alucard years ago and set in motion the ultimate incarnation of the Hellsing Organization. A wave of vampire attacks culminates in a deadly ambush of the Hellsing compound and draws attention to a shadowy group. After uncovering the Millennium organization's links to Nazis and the Vatican, Integra sends a delegation to Brazil to find out more.
The series was created after the Hellsing anime had finished, and was intended to be more true to the manga than the anime was. Over the course of the years, they have changed animation studios at multiple occasions. Hellsing Ultimate were animated by the animation studio Satelight, before Madhouse took over as of It was then announced that a new company would be animating the final three episodes of the series; Graphinica x Kelmadick, though it is still being produced by Geneon.
Hellsing: Ultimate I is the first installment of Hellsing: Ultimate. Hellsing Ultimate starts in the past, ten years ago. Integra, fearing for her life, flees to the bottom of the Hellsing mansion, where her " salvation " is. Richard and two other men follow her down there, and in an attempt to kill her by shooting her in the shoulder, accidentally awakens Alucard, who then proceeds to kill Richard's men.
The episodes of the Hellsing anime series premiered on Fuji Television on October 10, , and ran for thirteen episodes until its conclusion on January 16, Konaka ,  the episodes are based on the characters and settings of the Hellsing manga series by Kouta Hirano but lead through a different story. The episodes as a whole detail the works of the Hellsing Organization, a secret anti-paranormal unit under the command of Sir Integra Wingates Hellsing, and its various operatives including the vampire Alucard and his fledgling partner, ex-policewoman Seras Victoria.