Common law
The common lawso named because it was "common" to all the king's courts across Englandoriginated in the practices of the courts of the English kings in the centuries following the Norman Conquest in 1066. The British Empire spread the English legal system to its historical colonies, many of which retain the common law system today. These "common law systems" are legal systems that give great precedential weight to common law, and to the style of reasoning inherited from the English legal system.
Joint criminal enterprise
However, the origins of the doctrine may be influenced by the Common Law of England, which introduced the principle into criminal law in the UK and other Commonwealth nations such as Australia. A similar legal principle can also be found in Texas, USA, where it is known as the Law of Parties. The notion of collective liability and shared punishment for the actions of others as if all perpetrated the same deed may be much older, and was used to justify extermination of religious and cultural groups, such as the Albigensian "Heretics" and those who harbored them. Critics argue that Joint Criminal Enterprise can lead to excessive legal process and punishments, that it lowers the evidential bar in favour of prosecution, and that it runs counter to the spirit of Blackstone's formulation. Supporters argue that it ensures those contributing to or instigating a criminal act are properly made to account for their involvement.