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 land
Most commons are based on ancient rights under British common law, which pre-date statutes passed by the Parliament of England. The exact rights which apply to individual commons were in some cases documented, but more often were based on long-held traditions. A major reform began in 1965, with a national register of common land which recorded the land ownership and the rights of any commoners, and two other important statutes have followed.