Jan Valentine is one of the first vampires who is sent into to fight against Hellsing Organization Hellsing, He is considered a FREAK (A human turned into a Vampire using a FREAK chip, which allows to turn even non-virgins into vampires), Jan is the younger brother of Luke Valentine, The two of them have underworld ties.

Somehow they became part of the Millennium organization, It is believed that this group made Luke and Jan into Vampires and gave them an army of Ghouls to go after Hellsing.

Jan lead the army of Ghouls against Hellsing. He massacred almost all Hellsing men. The fight was going his way when all of a sudden, Walter C. Donez - the butler of Hellsing appeared killing most of the ghouls with his sharp, thin wires, a battle broke out between the two, Seras Victora joined the battle, destroying more ghouls with her cannon. But then, suddenly, Hellsing men appeared, turned into ghould make Walter and Seras go into slight shock. Then Seras temporarily turns into a real vampire and wipes out all the ghouls and the two Hellsing operatives overpower Jan and capture him.

During the integration of Jan, He let slip that he worked for Millennium. Shortly after he had said it his body burst into blue flames. The Major killed Jan out straight without warning becuase Jan failed and in order to hide who they where.