The visits to New Zealand and Australia by HRH Prince William have attracted considerable media attention. Whilst in New Zealand, the prince opened the new building of the Supreme Court of New Zealand – see BBC and NZ Supreme Court.
These nations and many others are all “common law” jurisdictions. Their law and legal system is based on that which developed in England and Wales and which was “exported” as people from these islands travelled and settled elsewhere. This does not mean that in modern times the law is identical in all of those countries but it does mean that the law is based on the same fundamental principles.
Within the courts of England and Wales, it is permissible to refer to – (or as lawyers say “cite”) - decisions of courts such as the supreme courts of other Commonwealth nations. They are referred to as “persuasive precedents” because they do not tie the hands of British judges but they might show the way forward on some difficult point of law.
Until quite recent times, many Commonwealth nations retained the Judicial Committee of the Privy Council as their ultimate court of appeal. Technically speaking, appeals to the judicial committee are “Appeals to Her Majesty in Council” though the case is heard by judges and “advises” Her Majesty as to the outcome of the case. This continues to be the position for those countries which retain appeals to the Privy Council. This court now sits in the same building as The Supreme Court of the U.K. and its judgments may be seen here.
The Common Law system differs markedly from other legal systems such as CIVIL law systems. A reasonably good description of civil law systems may be seen here and a particularly detailed study may be read at the website of the USA Federal Judicial Centre- (pdf file).
Other legal systems developed in Muslim nations – see, for example, the course offered by the School of Oriental and African Studies.
It must not be thought that legal systems invariably are influenced by only one of these (and other) systems. “Mixed “legal systems are far from uncommon and the reasons for this will be found in the history of the nation concerned.
Scotland and South Africa are two of the leading jurisdictions which integrate English common law with Continental civil law. Quebec in Canada has a legal system based very much on the civil law.
A student of English law in the 1960s would have studied almost only the common law system developed over the centuries by the judges and as altered, then quite minimally, by Parliament. This student would rarely have even looked across the English Channel to see the different legal systems of continental Europe though some students of the time might remember with some affection the "The Constitutional Law of Great Britain and the Commonwealth" by O. Hood Phillips. 50 years later, such insularity would be absurd. Since 1973, the U.K. has been a member of what has developed into the European Union and the jurisprudence of the Court of Justice of the European Union owes much to civil law. The U.K. has become multicultural and there are those who press for the law to take account of principles of other systems such as Shariah. Understanding of the different legal traditions of the world is now necessary and is to be encouraged.
Here are links to some of the major courts in the Commonwealth. It is quite a world tour:
Eastern Caribbean Supreme Court