Warning! Spoilers from the
Harry Potter series below!!!
Bellatrix Lestrange is a character in the Harry Potter book series by J.K. Rowling. Bellatrix is married to Rodulfus Lestrange, and is Sirius Black's cousin. Bellatrix has two sisters, Andromeada and Narcissa.
Bellatrix Lestrange is a Death Eater, a person who helps Voldemort. She was sent to Azkaban prison for the torture of Frank and Alice Longbottom.
In Harry Potter 5 (Harry Potter and the Order of the Phoenix) Bellatrix Lestrange escapes from Azkaban with help from Voldemort and other Death Eaters. At the end of the book she kills Sirius Black in the Department of Mysteries in the Ministry of Magic.