Bellatrix Lestrange is a fictional character from the Harry Potter series created by J.K. Rowling. She is a loyal follower of Lord Voldemort and is known for her sadistic personality and fierce loyalty to the Dark Arts. Bellatrix is a member of the Black family, a pure-blood wizarding family, and is often depicted as a powerful witch with a penchant for cruelty. In the series, Bellatrix plays a significant role in the fight against Harry Potter and his friends. She is responsible for several key events, including the torture of Neville Longbottom's parents and the death of Sirius Black, her own cousin. Her character embodies the themes of fanaticism and the dangers of unchecked power.