Bellatrix was born Bellatrix Black to Cygnus Black and Druella Rosier in the year 1951 and has two sisters, Andromeda (who was blasted off the Black Family tree for marrying Muggle-born Ted Tonks) and Narcissa. She is also a first cousin to Sirius and Regulus Black, and an aunt to Draco Malfoy and NymphadoraTonks. Bellatrix married Rodolphus Lestrange after leaving Hogwarts because it was "expected of her to marry a pure-blood". However, Rowling stated in an interview that Bellatrix's true love was Voldemort. InHarry Potter and the Goblet of Fire Rowling uses Dumbledore's Penesive as a Plot device to reveal that Bellatrix, rather than deserting Voldemort after his downfall like many other Death Eaters, is part of the group of dark wizards – along with Barty Crouch Jr, Rodolphus and Rabastan Lestrange – that torchered well-known Aurous Frank and Alice Longbottom in an attempt to gain information about Voldemort's location. For using the Unforgivable Cruciatus Curse to torture the Longbottoms to insanity, Bellatrix and her three associates were sentenced to life imprisonment in Azkaban. During the trial, she said Voldemort would rise again and reward them. When Voldemort rises again, he says the Lestranges went to Azkaban rather than renounce him and that they will be deeply rewarded when Azkaban is broken open.
Bellatrix Lestrange is the first female Death Eater introduced in the books, and the most faithful member of Voldemort's inner circle. She is described as being highly attractive yet emaciated due to her time in Azkaban. Bellatrix is portrayed as paranoid and fanatically devoted to Voldemort. She takes an obvious pleasure in acts of torture and cruelty, as demonstrated when she kills her cousin, Sirius Black. She is a witch of prodigious ability, as demonstrated by her many victories in duels against other characters, and as noted by Harry in the final book.