Luke Valentine is one of the first vampires who is sent into to fight Hellsing Organization along with his brother - Jan. He is considered a FREAK (A human turned into a Vampire by the aid of a FREAK chip, that allows to turn non-virgins into vampires), Luke is the Older brother of Jan Valentine. The two of them have underworld ties.

Somehow they became part of the Millennium organisation, It is believed that The Doctor made Luke and Jan into Vampires and gave them the army Ghouls to go after Hellsing.

Luke is always smartly dressed and try to pretend he comes from a higher class of humans when in fact he comes from the streets, During the battle at the Hellsing manor, Luke goes to the basement to search and fight Alucard, Hellsing’s number one weapon and trump card, Using two sawed of M1 grand rifles, they began to fight.

Luke displayed a remarkable talent in his speed and accuracy, But in the end Alucard won out. Releasing his restrictions, blowing off Luke's legs and using his hellhounds to devour Luke. Later Luke reappears when Walter C. Donez chops Alucard’s hellhound in half. The remains of Luke appear, and used by Walter to distract Alucrd, but due to some trickery by Alucard, Walter C. Donez kill’s Luke by accident.