Common law

Lore & Background

Initially, the common law referred to the laws common to all the king's courts across England, distinct from local folk courts, urban borough courts, and manorial courts. During the 12th century, Henry II established a system of travelling judges who enforced a set of laws common to all England. Over centuries, the precedent of these judges' decisions evolved into a sophisticated system of common law, which became the main form of lawmaking in England for hundreds of years. Compared to the civil law tradition of continental Europe, the common law tradition has markedly less influence from Roman law and less tendency to be codified, leaving common law judges broader discretion in statutory interpretation and a quasi-legislative function in adjudication. Nonetheless, early common law judges and scholars, including Glanvill and Bracton, were well accustomed with Roman law, and Bracton's treatise was heavily influenced by canon law and Justinian's Institutes. Roman law ideas regained importance in common-law legal scholarship with the revival of academic law schools in the 19th century. Separately, during the late medieval period, a distinct set of equitable laws began to be administered by the Court of Chancery. In the 17th century, it was established that where the rules of equity and common law conflicted, equity would prevail. In the late 19th century, the separate judicial systems of common law and equitable courts in England were fused, although the rules of equity were retained. Some jurisdictions, particularly in the United States, retain separate legal and equitable court systems.

Reader's Guide

The common law is significant as the foundation of legal systems in approximately one-third of the world's population, including major nations such as the United States, India, Canada, and Australia. Its defining feature is judge-made law based on precedent, which gives judges broad discretion in statutory interpretation and a quasi-legislative role. This contrasts with the civil law tradition of continental Europe, which relies more on codified statutes and Roman law. The common law's historical development from the King's courts of medieval England, particularly under Henry II's travelling judges, established a unified legal framework that replaced local customs. Over time, the common law system influenced and was influenced by Roman law, canon law, and equity. Today, common law countries increasingly adopt codes in areas such as bankruptcy, intellectual property, and tax law, exemplified by the Uniform Commercial Code in the United States. The legacy of the common law includes ongoing debates about judicial lawmaking, with early theorists viewing it as discovering ancient customs, while modern scholars adopt a positivistic or realist view. Mixed jurisdictions, such as South Africa and Scotland, incorporate both common law and civil law elements.

Did You Know?

• Henry II established a system of travelling judges during the 12th century, which helped create a set of laws common to all England.
• The term 'common law' has multiple distinct meanings, including judge-made law, the law common to the King's courts, and a legal system distinct from civil law.
• In the 17th century, it was established that where the rules of equity and common law conflicted, equity would prevail.
• Approximately one-third of the world's population lives in common law jurisdictions or mixed legal systems.

Defining the Boundaries of a Legal System

The question of what constitutes a legal system has generated considerable scholarly debate. John Henry Merryman offered one influential framing, describing a legal system as a functioning collection of legal institutions, procedures, and rules. However, the scope of this definition remains contested. Some scholars limit a legal system to the norms and laws issued by a particular sovereign authority or bound by a shared underlying rule, while others broaden it to encompass the institutions and processes through which those norms are interpreted and given practical effect. This distinction matters because it determines whether a legal system is understood as a static collection of rules or as a living, functioning apparatus. The terminology itself is not settled: while "legal order" and "legal system" are frequently used interchangeably, some legal positivists have drawn a temporal distinction between them, with theorists like Eugenio Bulygin and Carlos Alchourrón reserving "legal order" for the momentary state of the system, while others, including Andrzej Grabowski, apply the terms in the reverse sense.

Theoretical Foundations and Competing Models

The philosophical underpinnings of how legal systems are identified and distinguished have evolved significantly over two centuries. In the 19th century, John Austin proposed that legal systems should be differentiated by the sovereign from which their laws flow, an analysis echoing earlier work by Francisco de Vitoria. Under this framework, every law within a given system must trace back to the same sovereign legislator. Hans Kelsen, writing in the 20th century, shifted the focus to a single underlying basic norm from which all legal norms in a system must derive. H.L.A. Hart offered yet another positivist account, arguing that a legal system is defined by a shared rule of recognition that validates legal pronouncements. These models, however, face serious challenges from legal pluralism scholarship, which highlights that many legal norms emerge without any identifiable government or sovereign. H. Patrick Glenn went further, contending that the very concept of a legal system is structurally inadequate for capturing law's epistemic complexity, and advocated for legal traditions as a superior analytical unit.

Classification and the Rise of Mixed Systems

For much of legal scholarship, the dominant taxonomy divided the world's legal systems into civil law, common law, religious law, customary law, and mixed traditions. The civil law versus common law distinction once seemed clean, but modern observation reveals that the two groups have grown increasingly similar to one another while simultaneously becoming less internally cohesive. Some analysts have proposed additional categories, such as socialist legal systems or the Nordic tradition covering Scandinavia and Iceland, though these are more commonly treated as subgroups within civil law. A striking shift occurred in the late 20th century: mixed legal systems, previously overlooked in classification schemes, are now recognized as the most prevalent form. A 2000 study of world legal systems identified 92 mixed systems, 91 civil law systems, and only 42 common law systems. Contemporary scholarship has largely moved beyond these fixed categories, favoring an understanding of legal systems as drawing from multiple traditions and patterns simultaneously rather than fitting neatly into a single box.

Historical Biases in Legal Taxonomy

The history of legal system classification reveals how deeply geopolitical power and cultural assumptions have shaped scholarly frameworks. In 1909, Adhémar Esmein proposed a five-group classification—Roman, Germanic, Anglo-Saxon, Slavic, and Islamic—that mirrored the major global empires of his era. This scheme conspicuously omitted the legal traditions of Africa, China, and Japan, which Esmein deemed insignificant. Just four years later, in 1913, Georges Sauser-Hall advanced an explicitly racial taxonomy dividing legal systems into Indo-European, Semitic, and Mongolian categories. These early frameworks reflected the classifiers' views of geopolitical hierarchy rather than any neutral analytical principle. The comparative study of legal systems, which examines these structures across jurisdictions, and the abstract definition of legal systems, which falls largely within legal philosophy, both carry the imprint of these historical biases. Even today, questions remain about the status of international law as a legal system—Kelsen saw it as either embedded in all national systems or as an overarching structure, while Hart denied it system status due to the absence of a rule of recognition, change, or adjudication—though it is increasingly accepted as one.