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. Prior to the Norman Conquest, much of England's legal business took place in the local folk courts of its various shires and hundreds. A variety of other individual courts also existed across the land: urban boroughs and merchant fairs held their own courts, as did the universities of Oxford and Cambridge, and large landholders also held their own manorial and seigniorial courts as needed. Additionally, the Catholic Church operated its own court system that adjudicated issues of canon law.
Common Peace
With 'autonomy and freedom' the Greek states at the beginning of the fourth century found a formula for a inclusive peace system which was acceptable to all sides. After 387 BC no peace was possible without it, even if the individual attempts only held for a few years each. However, the principles of the common peace also found their way into league treaties, such as the Second Athenian Sea League and the League of Corinth. A major opportunity for the development of a true Common Peace lay in the fact that the peace idea proved flexible enough to be developed further in this way.