Narcissa Malfoy is Lucius' wife, Draco's mother and Bellatrix's sister from the Harry Potter series. Although she is closely tied to the Death Eater organization, she was never an official member herself.
She is portrayed by Helen McRory in the 6th, 7th and 8th movie.
Narcissa Black was the youngest daughter of Cygnus and Druella Black (née Rosier), born in 1955. She had two older sisters, Bellatrix and Andromeda. Narcissa was taught the philosophy of blood purity from a young age and grew up prejudiced in favour of pure-bloods. Thus, she cut off contact with her sister Andromeda after she was disowned for marrying Muggle-born wizard Ted Tonks and burned off the Black family tree.
Narcissa was educated at Hogwarts School of Witchcraft and Wizardry from c. 1966 – 1973 and was sorted into Slytherin House, where she met her future husband, Lucius Malfoy.
At some point after graduating from Hogwarts, likely in the late 1970s, Narcissa married Lucius Malfoy. The Malfoys lived a life of privilege and luxury at Malfoy Manor, located in the southern English county of Wiltshire. Her husband introduced Narcissa to the lifestyle of Death Eaters and loyalty to Lord Voldemort, though she never took the Dark Mark herself. They had one son, named Draco. Narcissa thus continued her family tradition of naming children after stars and constellations.
Narcissa's cousin Regulus Black was killed in the First Wizarding War, while her other cousin Sirius and sister Bellatrix were both sentenced to Azkaban after Voldemort's fall in 1981. Lucius was able to avoid a similar fate by claiming that he had been under the Imperius Curse, and the Malfoys remained members of the social elite. When Narcissa attended the Quidditch World Cup in 1994 with her husband and son, they watched the game from Minister for Magic Cornelius Fudge's luxury box.
When the time came for Draco Malfoy to begin school in 1991, Lucius Malfoy wanted him to attend Durmstrang Institute, which only admitted pure-blood and half-blood students, taught the Dark Arts, and is located somewhere in northern Europe. Narcissa, however, insisted that Draco Malfoy attend Hogwarts instead so he would be closer to home. She is very devoted to Draco, and sent him sweets and cakes by owl every day during his first year at Hogwarts.
Second Wizarding War
In 1996, Lucius participated in the Battle of the Department of Mysteries in an attempt to acquire a prophecy for Lord Voldemort, who had returned to power the previous year. The effort was thwarted by six D.A. members and the Order of the Phoenix. Voldemort was furious with Lucius, who had led the effort, both for failing to obtain the prophecy and for the consequences of that night, which included his return being admitted by the Ministry of Magic and many of his Death Eaters being sent to Azkaban, including Lucius himself. Narcissa was distraught over her husband's imprisonment as well as Voldemort's subsequent treatment of her family. That summer, she ventured to Severus Snape's home at Spinner's End, accompanied by her sister Bellatrix, to discuss Voldemort's plan for Draco to murder Hogwarts Headmaster Albus Dumbledore.
Narcissa was hysterical and theorized that Draco was being sent on a suicide mission to punish Lucius. Despite the pleading of her sister to the contrary, Narcissa brushed off Bellatrix scoffing when Bellatrix claimed that "The Dark Lord's mistaken," and Narcissa begged Severus to make an Unbreakable Vow, which ensured that he would watch over Draco during his efforts. She also made him vow to execute the plan himself, should Draco fail to do so. Later that month, she went shopping for school supplies with Draco at Madam Malkin's Robes for All Occasions. There she had a heated confrontation with Harry Potter. He taunted her about Lucius's imprisonment, and she responded by coldly alluding to the recent death of his godfather before haughtily departing with her son to Twilfitt and Tatting's.
Home as headquarters
By 1997, Malfoy Manor was being used as a headquarters for Voldemort. Meetings of Death Eaters were held there, and the murder of Charity Burbage took place in the drawing room. The Malfoys were extremely uncomfortable with having their home used for Voldemort's base of operations, but had no choice. They outwardly claimed that nothing pleased them more, but their later decisions would prove their feelings to the contrary. After Burbage's murder, Narcissa coaxed her husband into agreeing to give his wand to Voldemort; it was soon broken in the Battle over Little Whinging.
Voldemort was still displeased with the Malfoys for Lucius's earlier failures and delighted in humiliating them by bringing up their relation to werewolf Remus Lupin through Narcissa's niece, Nymphadora Tonks. Narcissa was also distressed by Voldemort forcing Draco to participate in Death Eater activities such as torturing the servants who displeased him.
Skirmish at Malfoy Manor
When Harry Potter, Ron Weasley and Hermione Granger were caught by a group of Snatchers led by Fenrir Greyback, they were brought to Malfoy Manor. Narcissa acted coldly and disdainfully towards Greyback, but let them in, where she called on her son to identify the prisoners and recognized Hermione from seeing her once in Madam Malkin's Robes for All Occasions. She seemed to clash with her sister over who had authority in her home, as well as over her protectiveness towards Draco. In her family's cellar already was Ollivander, Luna Lovegood, Dean Thomas and Griphook all being held prisoners for their own individual reasons. Later on Narcissa was shocked to see her family's former house-elf, Dobby, openly defying them.
After Harry and his friends escaped to Shell Cottage, Lord Voldemort severely punished Bellatrix and the Malfoy family. Narcissa also would give her wand to her son Draco to use after he returned to Hogwarts at the end of the Easter holidays, leaving both herself and her husband wandless.
Battle of Hogwarts
During the Battle of Hogwarts, Voldemort attempted to kill Harry Potter, once again with the Killing Curse. Narcissa was forced to check Harry's vital signs and used the opportunity, when she saw he was alive, to covertly ask Harry if he knew of Draco's well-being. In a whisper, she asked if Draco was alive. When Harry replied quietly that he was, Narcissa betrayed the Dark Lord and asserted Harry Potter was dead. When the battle recommenced, Narcissa and Lucius abandoned the Death Eaters and searched frantically for Draco. After the battle, the family was reunited in the Great Hall, where they were seen not quite knowing what to do with themselves. Because Narcissa betrayed Voldemort, the entire Malfoy family was granted a reprieve and avoided incarceration at Azkaban. Later on in Narcissa's life she would become a grandmother to Scorpius Malfoy, the son of her son and his wife Astoria Greengrass.