1310 Grimmauld Place was the ancestral home of the Black family. It was located in the Borough of Islington, London, in a Muggle neighbourhood, and the location was protected by a Fidelius Charm. As the house was invisible to the neighbourhood residents, the local Muggles have long since accepted the mistake in numbering which landed number 13 next to number 11.

In 1995, the home became the headquarters for the Order of the Phoenix with the consent of Sirius Black, with Albus Dumbledore becoming Secret-Keeper. After Dumbledore's death in 1997, everyone in whom he confided the location of 12 Grimmauld Place to became a Secret-Keeper.