This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
The reign of Henry II marks a great change in the development of English law. The king's court, whose law in the reign of Henry I had begun to tower above the popular customary law of the local courts in its terrible empire of kingly majesty, became a settled, organized and permanent tribunal whose jurisdiction had begun its career of growth and expansion which finally resulted in crushing out the law and the jurisdiction of the local courts. At the outset, however, the introduction of the king's courts into the judicial system merely added another element of confusion. We are so accustomed to feel that a nation must be a legal unit and that the courts should all attempt to administer the same law that it is difficult to realize that for centuries in England the theory which prevailed was the exact opposite of this. Because the custom of the king's courts finally crushed out the customs of the other courts and became the common law of England, the lex communis totius Angliae, we are likely to assume that the common law and the English law are synonymous terms; and that if contract was not recognized by the king's courts as a common law concept, it did not exist. In fact, each court had its own law. There was no common law. The hundred courts and the shire courts continued to administer popular tribal custom; and probably no court felt bound to make its customs comply with the customs of any other court. The manorial courts each applied the customs of the manor in which it was held. There was no reason why the customs of any two manors should agree. The courts of the church applied ecclesiastical law and their jurisdiction was invoked frequently for the very reason that the ecclesiastical law differed from the other systems. The merchants held their own courts in the trading towns and applied the law merchant which was the custom of the merchants of western Europe and of England. The law merchant was the law of a class and not the law of a nation. It was international law in the old sense of the term; that is, it was a law which was found in a great many different nations and which did not owe its existence or its validity to any one of them. It was a relic of the old theory of personal law.
1 Local King's Court in the Reign of Wm. I, by Geo. B. Adams, 23 Yale Law Jour. 490.
Over this system of courts each with its own law was imposed the system of the courts of the king. The law which this court administered at the outset looks to us to-day very much like a mixture of what we regard as common law in the proper sense and of equity. In fact, it was the material out of which both common law and equity developed. The theory that each court had its own law was assumed by the king's courts. When the organization of the king's courts into the king's bench, the common pleas and the exchequer took definite form, it was assumed that none of these courts was bound to adopt the customs of any one of the other courts. Even if one court had power to review the judgments of the other court, the inferior court was felt to have power to decide according to its own customs even though the defeated party was certain to secure a reversal if he could be heard by the superior court.1 With the growing tendency of the king's court to limit their jurisdiction and to petrify their fluid customs, the inherent power of the king to do justice in cases in which his courts could not do it, finally led to the formation of the court which was subsequently known as the court of the chancellor and to the formation of that system of rules which was finally known as equity. Here again, while equity purported to follow the law as far as it could, there was no reason why their rules should be the same on all questions; and, in fact, equity owes its very existence to the failure of the king's courts to do justice in specific cases. Furthermore, it was assumed by the king's courts at the outset that remedies must be exclusive and that they could not be concurrent. If a remedy for a given wrong existed, no other remedy could be given. The result was that the rights which were first recognized and protected by the king's courts were often protected by remedies inferior to those by which they protected rights which they did not recognize until a later stage of development.
1 An illustration of this is found in the determination of the Queen's Bench to allow indebitatus assumpsit without requiring an express promise to pay, although the Exchequer chamber kept reversing such judgments: Hinson v. Burridge, Moore, 701; Paramour v. Payne, Moore, 703; Maylard v. Kester, Moore, 711.
A much more recent illustration is found on question of procedure, in. Parker v. M'William, 6 Bing. 683.