In the 1860s the age of consent was twelve years old. Some people such as Josephine Butler and Barbara Bodichon were concerned that young girls were being sold to brothels. They became involved in the campaign against the white slave trade and in 1875 the House of Commons agreed to raise the age of consent to thirteen.

Campaigners were not satisfied with this change and continued to argue for further reform. In 1885 William Stead and Bramwell Booth of the Salvation Army joined forces to expose what they believed was an increase in child prostitution. In July 1885, Stead purchased Eliza Armstrong, a thirteen year-old daughter of a chimney-sweep, to show how easy it was to procure young girls for prostitution. Stead published an account of his investigations in the Pall Mall Gazette entitled Maiden Tribute of Modern Babylon.

In September, William Stead and five others were charged with unlawfully kidnapping a minor and committed for trial at the Old Bailey. Stead was found guilty and was imprisoned for three months in Holloway Gaol. As a result of the publicity that the Armstrong case generated, Parliament in 1885 passed the Criminal Law Amendment Act that raised the age of consent from thirteen to sixteen, strengthened existing legislation against prostitution and proscribed all homosexual relations.