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.
Certain types of contracts remained outside of the common-law rule which forbade assignment,1 as they remain outside of the modern-law rule that the assignee acquires only the rights of the assignor.2 These contracts, however, were controlled at the outset by the law-merchant, the law of the fair courts, or the courts of piepowder, or the staple courts,3 and not by the common law, the law of the king's courts.4 The law-merchant consisted originally of the customs of the merchants of western Europe and England. It was the law of a class which extended through a number of countries rather than the law of any one country. It was frequently spoken of as a branch of international law.5 In its original form the law-merchant included many subjects which we do not at present regard as law at all. The law-merchant was adopted by the common-law courts, at first with reference only to mercantile transactions between merchants,6 and at the outset to mercantile transactions between foreign merchants and English merchants.7