Jus commune or ius commune is Latin for "common law" in certain jurisdictions. It is often used by civil law jurists to refer to those aspects of the civil law system's invariant legal principles, sometimes called "the law of the land" in English law. While the ius commune was a secure point of reference in continental European legal systems, in England it was not a point of reference at all. (Ius commune is distinct from the term " common law" meaning the Anglo-American family of law as opposed to the civil law family.)
The phrase "the common law of the civil law systems" means those underlying laws that create a distinct legal system and are common to all its elements.
The , in its historical meaning, is commonly thought of as a combination of canon law and Roman law which formed the basis of a common system of legal thought in Western Europe from the rediscovery and reception of Justinian's Digest in the 12th and 13th centuries. In addition to this definition, the term also possibly had a narrower meaning depending upon the context in which it was used. Some scholars believe that the term, when used in the context of the ecclesiastical courts of England in the fourteenth and fifteenth century, also "meant the law that is common to the universal church, as opposed to the constitutions or special customs or privileges of any provincial church."
The was an actual part of the law in most areas, although in any one jurisdiction local laws (statutes and customs) could take precedence over the . This was the case up until the codification movement in the late 18th and 19th centuries, which explicitly removed the direct applicability of Roman and canon law in most countries, although there continued to be argument about whether the was banished completely or survived where the national codes were silent.
The latter view prevailed, so it can still be said that there is, in theory at least, a common basis in substantive law throughout Western Europe (except England, which never had a reception as such) although it has of course fragmented greatly from its heyday in the 15th and 16th centuries. More important, however, is the civilian tradition of ways of thinking that the encouraged and the procedures it used, which have been more persistent than the actual substance.
In England, the law developed its own tradition separate from the rest of Europe based on its own common law. Scotland has a mixed civil and common law system. Scotland had a reception of Roman law and partial codification through the works of the Institutional Writers, such as Viscount Stair and Baron Hume, among others. Influence from England has meant that Scotland's current system is more common law than civilian, but there are areas which are still heavily based on Roman law, such as Scots property law.