Catherine Eddowes was the fourth of the canonical five victims of the notorious unidentified serial killer known as Jack the Ripper, who is believed to have killed and mutilated a minimum of five women in the Whitechapel and Spitalfields districts of London from late August to early November 1888.

The "From Hell" letter was a letter sent with half of a preserved human kidney to George Lusk, the chairman of the Whitechapel Vigilance Committee, in October 1888. The author of this letter claimed to be the unidentified serial killer known as Jack the Ripper, who had murdered and mutilated at least four women in the Whitechapel and Spitalfields districts of London in the two months prior to Lusk receiving this letter, and whose vigilance committee Lusk led in civilian efforts to assist the police in identifying and apprehending the perpetrator.