This book examines Muslim efforts to incorporate sharia (religious law) into modern Indonesia's legal system from the time of independence in 1945 to the present. The book argues that attempts to formally implement sharia in Indonesia, the world's most populous Muslim state, have always been marked by tensions between the political aspirations of proponents and opponents of sharia and by resistance from the national government. As a result, although pro-sharia movements have made significant progress in recent years, sharia remains tightly confined within Indonesia's secular legal system. The book first places developments in Indonesia within a broad historical and geographic context, offering an analysis of the Ottoman empire's millet system and comparisons of different approaches to pro-sharia movements in other Muslim countries (Saudi Arabia, Iran, Pakistan). It then describes early aspirations for the formal implementation of sharia in Indonesia. Later chapters explore the efforts of Islamic parties in Indonesia to include sharia in national law. The book offers a detailed analysis of debates over the constitution and possible amendments to it concerning the obligation of Indonesian Muslims to follow Islamic law. A study of the Zakat Law illustrates the complicated relationship between the religious duties of Muslim citizens and the nonreligious character of the modern nation-state. The book concludes with a review of the profound conflicts and tensions found in the motivations behind Islamization.