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 Era
The expression has been traced back to 1615, when it first appeared in a book by Johannes Kepler as the Latin usage ", and to 1635 in English as "Vulgar Era." The term "Common Era" can be found in English as early as 1708, and became more widely used in the mid-19th century by Jewish religious scholars. In the later 20th century, the use of CE and BCE was popularized in academic and scientific publications, and more generally by authors and publishers wishing to emphasize sensitivity to non-Christians, by not explicitly referencing Jesus as "Christ" and "Dominus" ("Lord") through use of the abbreviation "AD".