Constitutions of today do not merely address the salus populi anymore, the welfare of the people, but increasingly exhibit international ambitions. This is true in particular for the EU Treaties. To make sense of these developments, this thesis presents a comprehensive account of foreign policy objectives as a growing part of European constitutional law. It grasps these provisions as legal norms, discerns their legal force and functions, and situates them into the overall legal order of the state, the Union, and the composite 'European Constitutional Space’. It argues that for comparative constitutional law in general, the codification of foreign policy objectives suggests a step forward in the evolution of the role of the constitution: From limiting public authority to guiding it towards certain goals, both at home and in the world. For the EU in particular, this research advances a comparative constitutional perspective for the study of EU external relations, and adds a constitutional dimension to the 'normative power’ debate in the study of EU foreign policy. Drawing on established national doctrines on constitutional objectives from Germany, France and India, the thesis elaborates a common vocabulary for understanding foreign policy objectives across different jurisdictions. It adapts these findings to the pluralist context of the Union and its Member States, which closely intertwines both legal orders and foreign policies. It reveals that constitutional foreign policy objectives represent norms of constitutional rank which commit a polity to an active and 'normative’ foreign policy, serving principally as an interpretive lens through which public powers can be enlarged. As a feature peculiar to the EU context, such objectives help to channel the individual ambitions of the Member States through the Union framework towards a more coherent, albeit polyphonic, external action. Furthermore, the project feeds its legal findings into the debate on the EU as an actor in International Relations, drawing on the main IR theories to sharpen the analysis of these norms in inter-institutional struggles as well in long-term processes of identity-shaping, legitimation and socialization.