Number Twelve, Grimmauld Place

• Type: Residence, Headquarters
• Location: Borough of Islington, London, England
• Owner/Residents: House of Black (formerly), Sirius Black, Order of the Phoenix, Harry Potter, Kreacher
• Key Features: Unplottable, protected by the Fidelius Charm, hidden from Muggles, filled with Dark Arts artifacts and historical remnants of the House of Black.

Number Twelve, Grimmauld Place is the ancestral home of the House of Black, an ancient and wealthy pure-blood wizarding family fanatically devoted to blood purity. The house itself is a grim, multi-story Georgian terrace house located in a Muggle neighborhood in London. To protect its occupants, the house was made Unplottable and hidden by a powerful Fidelius Charm, rendering it invisible and inaccessible to anyone not told of its specific location by the Secret-Keeper. It is physically wedged between numbers eleven and thirteen, which appear to be seamless neighbors to the outside world. The interior of the house reflects the dark history and prejudices of its former owners. It is depicted as gloomy, dusty, and dilapidated, with serpent-themed decorations, peeling wallpaper, and threadbare carpets. The entrance hall contains a troll-leg umbrella stand and is dominated by a life-sized, enchanted portrait of Walburga Black which shrieks insults at visitors. Other grim decorations include the severed heads of former house-elves mounted on plaques on the staircase. Sirius Black, the last heir of the Black family, despised the house and everything it stood for. After escaping from Azkaban, he offered it to Albus Dumbledore to serve as the headquarters for the reinstated Order of the Phoenix during the Second Wizarding War. Dumbledore himself became the Secret-Keeper for the Fidelius Charm. Following Dumbledore's death, a loophole in the charm meant that everyone he had told the secret to, including Severus Snape, became a Secret-Keeper. This compromised the location's security, forcing the Order of the Phoenix to abandon it. Alastor Moody placed a Tongue-Tying Curse on the image of Snape within the house to prevent him from revealing the location to Lord Voldemort. After Sirius's death, the house and its resident house-elf, Kreacher, were bequeathed to Harry Potter. Harry, Ron Weasley, and Hermione Granger later used it as a sanctuary during their hunt for Voldemort's Horcruxes. Their stay ended abruptly when the Death Eater Yaxley managed to grab hold of Hermione as she Disapparated, breaking the protective enchantments and forcing the trio to flee permanently.

Number Twelve, Grimmauld Place is a central location in Harry Potter and the Order of the Phoenix. It functions as the nerve center for the resistance against Lord Voldemort, where members meet, strategize, and live. For Harry Potter, it represents a first look into the organized adult world fighting the Dark Arts. For Sirius Black, it is simultaneously a safe house and a prison, as his status as a wanted fugitive prevents him from leaving. The house is also a powerful symbol of the decay of pure-blood supremacy. Its dark and neglected state mirrors the decline and corruption of the House of Black's ideology. The cleaning efforts by the Weasley family and other Order members represent a symbolic purification of the house's dark past. In Harry Potter and the Deathly Hallows, the house becomes a crucial refuge for Harry, Ron, and Hermione. It is also where the full story of Regulus Arcturus Black and the history of Salazar Slytherin's Locket is uncovered through Kreacher, making it instrumental to the Horcrux hunt.

• Entrance Hall: A long, high-ceilinged hall featuring gas lamps, ancient portraits, and the shrieking portrait of Walburga Black, which is concealed behind moth-eaten curtains.
• Basement Kitchen: A cavernous, shadowy room with rough stone walls, a large fireplace, and a long wooden table that served as the primary meeting place for the Order of the Phoenix.
• Drawing Room: An elegant but decaying room on the first floor. Its main feature is the vast Black family tree tapestry, which traces the family's lineage back to the Middle Ages. Names of disowned family members, such as Sirius Black and Andromeda Tonks, are visibly burned off the fabric.
• Sirius's Bedroom: Located on an upper floor, this room stands in stark contrast to the rest of the house. Sirius had decorated it in his youth with Gryffindor banners, posters of Muggle motorcycles and girls, and a permanent sticking charm to defy his parents' values.
• Other Bedrooms: The house contains numerous bedrooms, many of which are gloomy and unwelcoming. Harry and Ron share one containing a wardrobe that houses a Boggart. Buckbeak the Hippogriff was kept in the former bedroom of Sirius's mother.

• The name “Grimmauld Place” is a pun on “grim old place,” aptly describing the house's atmosphere.
• In the film adaptation of Harry Potter and the Order of the Phoenix, the house is shown magically pushing its way into view from between numbers 11 and 13, a visual effect that became an iconic representation of wizarding concealment. (film)
• The Black family tree tapestry was created as a large, intricate prop for the film, hand-painted on canvas to look like ancient woven material. (film)