Combination and Conspiracy covers the formative era of English labour 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 favourable legal regime. The notorious Combination 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 law of conspiracy. This book rescues from obscurity the Molestation of Workmen Act in the mid-nineteenth century, the product of a curious collaboration by trade unionists and Conservative politicians, and integrates it with changing notions of contract as the basis of industrial relations. Finally, the book presents the foundations of modern labour law, the legislation of the 1870s (as amended in 1906), as the culmination of a centuries-long process of statutory and precedential development.