The libel trial instigated by Irish author Oscar Wilde (pictured) began, eventually resulting in his arrest, trial and imprisonment on charges of gross indecency.

Defamation is a communication that injures a third party's reputation and causes a legally redressable injury. The precise legal definition of defamation varies from country to country. It is not necessarily restricted to making assertions that are falsifiable, and can extend to concepts that are more abstract than reputation such as dignity and honour.

Oscar Fingal O'Fflahertie Wills Wilde was an Irish author, poet, and playwright. After writing in different literary styles throughout the 1880s, he became one of the most popular and influential dramatists in London in the early 1890s. Regarded by most commentators as the greatest playwright of the Victorian era, Wilde is best remembered for his Gothic novel The Picture of Dorian Gray (1890), his epigrams, plays, and bedtime stories for children, as well as his criminal conviction in 1895 for gross indecency for homosexual acts.

Section 11 of the Criminal Law Amendment Act 1885, commonly known as the Labouchère Amendment, made "gross indecency" a crime in the United Kingdom. In practice, the law was used broadly to prosecute male homosexuals where actual sodomy could not be proven. The penalty of life imprisonment for sodomy was also so harsh that successful prosecutions were rare. The new law was much more enforceable. In England and Wales, section 11 was repealed and re-enacted by section 13 of the Sexual Offences Act 1956; this in turn was repealed by the Sexual Offences Act 1967, which partially decriminalised male homosexual behaviour.