The dissertation presents a theoretically controlled and historically informed inquiry into the formation and dynamics of the European system of states between the 8th and the 18th Centuries. It combines two methods of research and exposition. First, it pursues a comparative-chronological approach by elaborating and contrasting historically diverse logics of territorial and international order - exemplified with reference to the medieval, the early modern, and, partially, the modern geopolitical systems. Second, it adopts a developmental perspective by supplementing the systematic-comparative but static account of geopolitical orders with a more narrative, yet theoretically hedged, exposition of their incommensurable conflictual dynamics and expansionist drives. This processual perspective allows us to address the crucial question of the causes behind the passage from one geopolitical order to another. Contrary to conventional assumptions in the theory of international relations, the thesis is that the diversity of geopolitical systems and the reasons behind their transformations are bound up with different and changing social property relations in the domestic sphere. These social property relations govern the very identity of the constitutive actors of any geopolitical system and inform their modes of territorial order and foreign policy behaviour. Such a thesis has direct implications for a fundamental re-interpretation and re-periodisation of the origins of modern international relations, commonly associated with the Westphalian Peace settlements of 1648. By embedding the demystification of 1648's essential modernity in the wider continuum of European history, the dissertation shows to which degree early modern geopolitics remained tied to its medieval roots. The old pre-modern logic of geopolitical relations is only challenged with the advent of a new social property regime and the articulation of a new state/society complex in late 17th Century England, which starts in the 18th Century to transform the state system of the Old Regime into a modern system of sovereign states