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.
Roman law
By the middle of the 16th century, the rediscovered Roman law dominated the legal practice of many European countries. A legal system, in which Roman law was mixed with elements of canon law and of Germanic custom, especially feudal law, had emerged. This legal system, which was common to all of continental Europe (and Scotland) was known as "Ius Commune". This "Ius Commune" and the legal systems based on it are usually referred to as civil law in English-speaking countries.