During this period, and indeed for several centuries later, the industry was free from labor troubles. The reason, however, is to be found in the peculiar situation which existed under English law. Under English common law all combinations of workmen were considered as contrary to public policy, regarded as combinations in restraint of trade, and dealt with very harshly. A single workman might work or refuse to work for whatever pay or under whatever conditions he pleased, but an agreement of two or more on this basis, that is to combine for pay, hours, and the like, was a criminal conspiracy. Not only were any agreements such a group of men might make absolutely void, but the very fact of entering such a combination was itself a criminal offence. From the reign of Edward I (1272–1307) to George IV (1820–1830) thirty or forty acts of Parliament, commonly called “Statutes of Laborers,” were passed on this basis. The reënactment of legislation on this subject from time to time was not caused, as is usual in such cases, by the ineffectiveness of the legislation but by the necessity of meeting special conditions which were created by visitations of the plague, wars, and other events having far-reaching industrial effects. The development of the factory system of production, beginning about the middle of the eighteenth century, with the consequent gathering of great groups of workmen in certain localities and the rapid increase in the town population, rendered a continuance of the old regulations more and more difficult. The laws against combinations of workmen were evaded by the organization of secret societies, while the displacement of large numbers of hand workers by the introduction of machinery caused serious labor troubles and rioting. Other conditions too familiar to need description arose which caused friction between the workmen and their employers. Attempts were made at first to put a stop to the combinations of the workmen by more and more stringent legislation. This proving unsuccessful, the legislation was modified in the direction of leniency. Gradually the unions won their way to recognition, although this recognition was developed in the slow and inconsistent way which is common with English legislation.