Following the assassination of Henri IV in 1610, the political turbulence of Louis XIII's early reign led to renewed efforts to police the book trade. Yet this period also witnessed a golden age of so-called 'libertine' literature, including a plethora of sexually explicit and irreverent poetry as well as works of free-thinking that cast doubt on the dogma of Church and State. As France moved closer towards absolutism, a number of unorthodox writers were forced to defend themselves before the law courts. Libertines and the Law examines the notorious trials of three subversive authors. The Italian naturalist philosopher Giulio Cesare Vanini was brutally executed for blasphemy by the Parlement de Toulouse in 1619. The Jewish convert Jean Fontanier was burned at the stake two years later in Paris for authoring a text refuting Christian teaching. Finally, the trial of the infamous poet Théophile de Viau for irreligion, obscenity, and poetic descriptions of homosexuality proved to be a landmark in French literary and social history, despite the poet eventually escaping the death penalty in 1625. These trials are contextualised with a conceptual history of libertinism, as well as an exploration of literary censorship and the mechanics of the criminal justice system in early modern France. Drawing from rarely explored archival sources, newly discovered evidence, and legal manuals, Libertines and the Law provides new insights into the censorship of French literature and thought from the perspectives of both the defendants and the magistrates. Through a diverse corpus including poetry, philosophical texts, religious polemics, Jewish teachings, and private memoirs, it sheds new light on this crucial period in literary, legal, and intellectual history.