Bellatrix Lestrange

Bellatrix Lestrange (née Black), also known as Bella, is a pure-blood witch and a follower of Lord Voldemort in the world of Harry Potter, where she serves as the secondary antagonist of the series. She is portayed by Helena Bonham Carter in the films.

History
Bellatrix Lestrange was born to Cygnus and Druella Black in 1951. After graduating from Hogwarts, she became one of Voldemort's most important, and possibly most sadistic, followers, known as the Death Eaters. Bellatrix was one of the few females in the group, and was the wife of Rodolphus Lestrange. She, along with her husband, was imprisoned in the wizard prison Azkaban after torturing Frank and Alice Longbottom into insanity using the Cruciatus Curse, her specialty spell.

During Voldemort's second rise to power in 1996, Bellatrix escaped along with many other Death Eaters. She later participated in the Battle of the Department of Mysteries, where she taunted Neville Longbottom and killed her cousin Sirius Black.

Bellatrix was killed by Molly Weasley during the Battle of Hogwarts on May 2, 1998.

Plot
n the films, Bellatrix serves as the secondary antagonist in Order of the Phoenix and assumes the role of the main antagonist of ''Half-Blood Prince. She returns to her role as the secondary antagonist in Deathly Hallows Part 1 and Deathly Hallows Part 2''. She is also the secondary antagonist in the series overall due to her arguably being Voldemort's most evil, violent, and loyal supporter. Her role is expanded a bit in the films, although she does not appear in the trial scene in Harry Potter and the Goblet of Fire, with Karkaroff testifying against [http://villains.wikia.com/wiki/Barty_Crouch_Jr. Barty Crouch Jr.], the only Death Eater equal to Bellatrix in insanity and loyalty to Voldemort, who took part in the torture of Frank and Alice Longbottom. Bellatrix was the main torturer, as mentioned by Neville.

In Harry Potter and the Order of the Phoenix, Bellatrix was broken out of Azkaban by Voldemort and some of his Death Eaters, along with Antonin Dolohov and many other Death Eaters. Bellatrix and Lucius Malfoy later led the Death Eaters in the Department of Mysteries to take the Prophecy from Harry when Voldemort tricked him into retrieving it. Eventually, Sirius arrived with Remus Lupin, Nymphadora Tonks, Kingsley Shacklebolt, and Alastor "Mad-Eye" Moody, and he and Harry defeated Lucius and Dolohov. Bellatrix then killed Sirius with the Avada Kedavra curse, and he fell into the archway and disappeared. An enraged Harry attempted to use the Cruciatus Curse on Bellatrix, but was unable to perform the spell correctly as, according to Voldemort, he had to "mean it." When Albus Dumbledore arrived to duel Voldemort, Bellatrix escaped through the fireplace.

In Harry Potter and the Half-Blood Prince, Bellatrix and her sister Narcissa Malfoy had Severus Snape make the Unbreakable Vow to protect Draco Malfoy and kill Dumbledore should Draco fail to do so. She also burned down the Burrow at one point, although it was later rebuilt afterward. After Snape killed Dumbledore, Bellatrix attacked Hogwart's Great Hall and Hagrid's hut, setting it on fire despite it being made of stone.

In Harry Potter and the Deathly Hallows, Part 1, Bellatrix wanted to kill Harry, but Voldemort said that he must be the one to kill him. At some point before his death, Dumbledore gave a fake Sword of Gryffindor to Snape, who gave it to Voldemort, who entrusted it to Bellatrix, who kept it in her vault at the wizards' bank Gringotts. When Snatchers, led by Scabior, took Harry, Ron Weasley, and Hermione Granger to Malfoy Manor, Bellatrix saw the Sword of Gryffindor and thought that Harry had broken into her vault, so she tortured Hermione for information, carving the word "Mudblood" into her arm. Then she questioned Griphook about the sword and decided to kill Hermione; however, Ron disarmed her before she could. Later, Dobby sent a chandelier crashing down toward Bellatrix, who avoided it, and as Dobby Disapparated with Harry, Ron, Hermione, and Griphook, Bellatrix threw her knife at him, killing him.

Hermione later disguised herself as Bellatrix to get into her vault in Gringotts, wich was guarded by a dragon; Bellatrix never knew of this. It is presumed that, in Harry Potter and the Deathly Hallows Part 2, Bellatrix was the one who killed Tonks as in the book, since Tonks's death is never shown on-screen. When she nearly kills Ginny with Avada Kedavra, Molly Weasley fights Bellatrix in a rage, petrifies her, and destroys her with what is likely the Reducto charm. Bellatrix never thought that Molly would defeat and kill her.