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.
Admiralty law
Common law legal systems of Britain and the United States are in contrast to civil law legal systems which prevail in continental Europe and trace back to old Roman codified law. Although England's admiralty law was a development of continental civil law, its admiralty courts were common law courts, albeit somewhat distanced from the mainstream Kings Bench.