The Hellsing Organization, in the manga and anime series "Hellsing," is a secret British group dedicated to combating supernatural threats, particularly vampires and ghouls. Led by Sir Integra Hellsing, they deploy powerful vampires like Alucard to hunt and eliminate these threats, protecting humanity from the supernatural underworld. The organization operates with strict secrecy and utilizes advanced weaponry and ancient knowledge to confront and neutralize these supernatural dangers.