This book makes a critical contribution to the growing literature on constitutional unamendability, as well as to the broader scholarship in the field of comparative constitutional change. It represents a unique analysis of unamendability in democratic constitutionalism that engages critically and systematically with its perils, offering a much-needed corrective to existing understandings of this phenomenon. This book takes seriously the democratic challenge that eternity clauses pose and argues that this goes beyond the old tension between constitutionalism and democracy. It adopts a contextual approach that allows for more nuanced understandings of constitutional amendment rules and substantive limits on amendments. It also looks beyond the usual suspects typically discussed in this literature and brings to the fore a variety of case studies from non-traditional jurisdictions. Together, these insights illuminate the prospects of unamendability fulfilling its main intended aim, that of protecting constitutional democracy.