Rylands v Fletcher [1868] UKHL 1 was a decision by the House of Lords

Judicial functions of the House of Lords

The House of Lords, in addition to having a legislative function, historically also had a judicial function. It functioned as a court of first instance for the trials of peers, for impeachment cases, and as a court of last resort within the United Kingdom. In the latter case the House's...

 which established a new area of English tort law

English tort law

English tort law concerns civil wrongs, as distinguished from criminal wrongs, in the law of England and Wales. Some wrongs are the concern of the state, and so the police can enforce the law on the wrongdoers in court – in a criminal case...

. Rylands employed contractors to build a reservoir, playing no active role in its construction. When the contractors discovered a series of old coal shafts improperly filled with debris, they chose to continue work rather than properly blocking them up.