Since Roman times, the lapse of time has entailed a legal effect. The present thesis focuses on a specific aspect of the lapse of time: the loss of a right to bring a claim before an international tribunal, known as extinctive prescription. The thesis provides a comprehensive analysis of extinctive prescription in international law, examining its application by international courts and tribunals, clarifying its status within international law sources as a general principle of law, and determining the constitutive elements that trigger its application. Moreover, specific issues that arise in practice when determining whether a claim is time-barred are addressed, such as the starting point, the suspension, and the interruption of the limitation period. The thesis contributes to the existing but outdated scholarship on the subject in international law, enhances our understanding of extinctive prescription and its role in international dispute settlement, and provides a foundation for a clearer application of the principle by international adjudicators.