Combination and Conspiracy covers the formative era of English Labor law, from the eighteenth century when organizations of skilled workers emerged from the guild system to the early twentieth century when national unions used their democratic political power to secure a favorable legal regime. The notorious Combinations Acts of 1799 and 1800 are placed firmly in the context of the preceding series of statutes for particular trades and places, as well as related to the developing common law of criminal conspiracy. The Molestation of Workman Act in the mid-nineteenth century, the product of a curious collaboration by trade unionists and conservative politicians, is rescued from obscurity and integrated with changing notions of contract as the basis for industrial relations. Finally, the foundations of modern labor law, the legislation of the 1870s (as amended in 1906), are presented as the culmination of a centuries-long process of statutory and precedential development.