Selene is the main protagonist of the Underworld films. She's portrayed by Kate Beckinsale.
Early Life, Tragedy, and Becoming a Vampire
Selene was born to a Hungarian family sometime in the year 1383. Her father was a well-known architect who helped design a fortress for a Vampire general named Viktor. The fortress was, in reality, a dungeon intended for the imprisonment of the Werewolf William Corvinus, who was condemned for his bloody and destructive behaviour.
After Lycans supposedly killed her family, Selene was the only surviving human who had walked through the corridors of the fortress. She did not know, however, that her family was slain by Viktor himself, and not by the Lycans. She believed Viktor saved her.
She became a Death Dealer, fighting the war against the Lycans for revenge. Kraven, the Coven’s regent, was obsessed with her, though she did not return the feelings. She once exiled the Official Historian, Andreas Tanis, on Viktor’s orders, although the two seemed to have a grudging respect for each other.
The End of The War & Revelations
After a confrontation with the Lycan hit man, Raze, Selene discovers what is supposedly a Lycan lair. Not knowing that Kraven was in league with the Lycan leader, Lucian, to take over the Vampire realm from the Elders, she was angry when he dismissed her claims.
She tracked down the human she believed the Lycans had an interest in: Michael Corvin. Against the sacred rules of the covenant, she and the lycanthropy disease infected Michael fell in love. She awakened Viktor from his slumber, believing that only he had the power to deal with the conspiracy between Kraven and Lucian. She then led a mass assault on the Lycans’ underground bunker. After Michael is shot by a jealous Kraven, Selene is forced to infect Michael with her Vampire virus strain, thus making him the first Lycan-Vampire Hybrid. She also learned the truth about her family’s murder from Kraven, and she struck down Viktor while the Elder was busy fighting Michael, most likely out of vengeance and to save Michael. She then retrieved Sonja’s pendant, carrying on the legacy.
Death of The First Immortals & The New Era
After Viktor’s death, Selene and Michael go on the run from both Lycans and Vampires. Selene is confronted by Marcus, the last surviving Vampire Elder. As Marcus attacks her for Sonja’s pendant, Michael intervenes and fights Marcus to protect Selene. After narrowly escaping Marcus and the coming sunlight, Selene and Michael take refuge in a warehouse. In the warehouse Michael attempts to tend to Selene's burn wounds, only to discover they have already healed. While hiding in the warehouse, the two become lovers.
To find out why Marcus was after the pendant, she seeks out Andreas Tanis. Tanis tells her the truth about her family’s slaughter and reveals to her that Marcus, not Viktor, is the original Vampire. He then sets up a meeting for her and Michael with Alexander Corvinus (who he calls Lorenz Macro, his alias), Marcus’ father and the first true immortal.
Selene becomes angry with Alexander (after realizing who he was due to his ring) for not removing the threats his sons posed long ago. Alexander then retorts by asking her if she would murder her own son. An interruption by Marcus in which Michael is seemingly killed results is Selene’s memories of the fortress to be taken by Marcus through her blood. Alexander tells Selene that the only way to defeat Marcus and William would be to drink his blood, adding that she would become the “Future”. Selene gains greater strength and new powers from Alexander’s blood. All through this exchange, she is grief-stricken over the loss of Michael.
Selene and a squad of Alexander’s ‘Cleaners’ invade William’s dungeon, trying to stop the threat. They arrive too late, however, and Selene is forced to fight Marcus. Marcus is shocked to smell his father’s blood flowing through Selene’s veins. After locking Marcus in William’s dungeon, Selene discovers that William has infected all the Cleaners, who then become Lycans themselves. On the verge of being overwhelmed, she is saved by Michael, who has regenerated due to his Hybrid powers. Selene fights Marcus once more, and the Elder drives his wing talon through her chest. Empowered by Alexander’s blood, Selene tears away the talon and drives it into Marcus’ skull before throwing him into the helicopter blades, thus killing him.
After Marcus and William are killed, Selene discovers that she is able to stand in the sunlight due to the pure Corvinus Strain from Alexander Corvinus. It phenomenally enhances her strength and healing to a level equivalent to that of a Vampire-dominate Hybrid.
Awakening and The New War against Humanity
Sometime after her victory over Marcus and William, she was captured by humans and was kept in hibernation. After twelve years, she awakens to a world that now knows of vampires and lycans. Humans now hunts down both races. Selene must contend against humanity and their new creation all the while she is searching for Michael Corvin.