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.
Common purpose
The common purpose doctrine was established in England and Wales, and later adopted in other common-law jurisdictions including Scotland, Ireland, Australia, Trinidad and Tobago, the Solomon Islands, Texas, Massachusetts, the International Criminal Court, and the International Criminal Tribunal for the former Yugoslavia.