This book provides a critical introduction to Chile's constitutional system, covering its key elements. It provides: - an account of its historical origins; - the structure of the different branches of government; - the way the fundamental rights are recognised and guaranteed; - the recent judicialisation of politics experienced by the country. Furthermore, the volume addresses three crucial themes of Chile's constitutionalism that have received little scholarly attention. First, the early development of a constitutional state, toward the mid-19th century, in a region then plagued with state-formation problems, civil war, and authoritarian regimes. Second, the irruption of a military dictatorship that lasted 17 years (1973-1990) in a country that had achieved a decades-old constitutional democracy. And third, the persistent lack of legitimacy of the Constitution of 1980, after more than a quarter of a century during which it governed what was generally considered to be a successful transition to democracy, following the dictatorial regime of General Augusto Pinochet.