law

Body of rules and principles under which justice is administered or order enforced in a state or nation. In Western Europe there are two main systems: Roman law and English law. US law is a modified form of English law.

Roman law
The legal system of ancient Rome is now the basis of civil law, one of the main European legal systems. It began under the republic, was developed under the empire, and continued in use in the Byzantine Empire until 1453. First codified 450 BC, and finalized under Justinian AD 528–534, it advanced to a system of international law (jus gentium), applied in disputes between Romans and foreigners or provincials, or between provincials of different states. Church influence led to the adoption of Roman law throughout western continental Europe, and it was spread to Eastern Europe and parts of Asia by the French Code Napoléon in the 19th century. Scotland and Québec (because of their French links) and South Africa (because of its link with the Netherlands) also have it as the basis of their legal systems.

English law
has its roots in Anglo‐Saxon customs, which were too firmly established to be broken by the Norman Conquest and still form the basis of the common law, which by 1250 had been systematized by the royal judges. Unique to English law is the doctrine, or principle, of stare decisis (Latin ‘to stand by things decided’), which requires that courts abide by former precedents (or decisions) when the same points arise again in litigation (law suits).

English reforms
The system of equity developed in the Court of Chancery, where the Lord Chancellor considered petitions, and the ordinary rules were mitigated where their application would operate harshly in some cases.

In the 19th century there was major reform of the law (for example, the abolition of many capital offences, in which juries would not in any case convict) and of the complex system of law courts.

Comparison of Roman and English law
The main differences between the British legal system, called the accusatorial or adversarial system, and the system of some European countries (for example, France), called the inquisitorial system, are that in the accusatorial system the judge acts as an impartial umpire; prosecution and defence each put their case; and the jury decides. In the inquisitorial system the inquiry into the facts is conducted by the judge, who also examines the evidence and interrogates witnesses.

A disadvantage of the accusatorial system is that juries have to decide on the basis of the evidence put in court, which may be limited by rules of evidence. The same evidence would not be hidden under the inquisitorial system, where all evidence must be put forward. But the inquisitorial system does not allow for cross‐examination of witnesses, and gives the examining magistrate potentially‐oppressive powers. Pleas of guilty are also not allowed.