Underworld is a series of vampire/werewolf films directed by Len Wiseman

Len Wiseman

Len Ryan Wiseman is an American film director best known for his work on the Underworld series and Live Free or Die Hard. His latest project, Total Recall, is set for release in summer 2012...

 and Patrick Tatopoulos

Patrick Tatopoulos

Patrick Tatopoulos is a French-Greek production designer, who lives and works in the United States. His designs have appeared in numerous motion pictures, including Pitch Black, Underworld, I, Robot, The Chronicles of Riddick, Independence Day, Bram Stoker's Dracula, Stargate, Spawn, Godzilla,...

. The first film, Underworld

Underworld (2003 film)

Underworld is a 2003 action-horror film about the secret history of Vampires and Lycans . It is the first installment in the Underworld series. The main plot revolves around Selene , a vampire who is a Death Dealer hunting Lycans...

, was released in 2003, and the second film, Underworld: Evolution

Underworld: Evolution

Underworld: Evolution is the second installment in the Underworld series, following Underworld in 2003...

, was released in 2006. A prequel, Underworld: Rise of the Lycans

Underworld: Rise of the Lycans

Underworld: Rise of the Lycans is a 2009 American film directed by Patrick Tatopoulos. It is the third installment in the Underworld series, focusing primarily on the origins of some characters and the events leading to the Vampire-Lycan war, depicted in the previous films Underworld and...

, was released on January 23, 2009. A fourth film, Underworld: Awakening, is in post-production for 2012 release.
Underworld tells the story of Selene

Selene (Underworld)

Selene is a fictional character from the Underworld film series. She is the main protagonist in both Underworld and Underworld: Evolution, portrayed by Kate Beckinsale and also by Beckinsale's daughter, Lily Mo Sheen, in Underworld: Evolution in flashback scenes as a child. Selene was created by...

 (Kate Beckinsale

Kate Beckinsale

Kathryn Bailey "Kate" Beckinsale is an English actress. After some minor television roles, she made her film debut in Much Ado About Nothing while still a student at Oxford University...

), a Death Dealer bent on destroying the Lycans

Lycanthropy

Lycanthropy is the professed ability or power of a human being to undergo transformation into a werewolf, or to gain wolf-like characteristics. The term comes from Greek Lykànthropos : λύκος, lykos + άνθρωπος, ànthrōpos...

 who allegedly killed her family.