Medieval Geopolitics: The Invention of the Idea of Sovereignty

By Andrew Latham

In my recent columns, I have described how new political ideas emerging after about AD 1200 provided a blueprint for a new political structure (the state), and how the military, fiscal and judicial revolutions provided the means to actually build such a structure.  In future columns I will examine the ways in which the process of state building triggered by these developments gave rise to several distinct, but closely related, types of state: the Empire, kingdoms, principalities, leagues and even the Church-state. In this column, I trace on the evolution of the idea of “sovereignty,” which I believe to be the conceptual linchpin of this historical process.

13th century depiction of the Pope – from Liber Floridus, folio 99.

The crystallization of the idea of sovereignty was a complex phenomenon that began not with Bodin or Hobbes in the 16th century, but with the re-introduction of Roman law to Latin Christendom in the late 11th. Classical Roman law, of course, held that the emperor enjoyed supreme imperium or potestas – that is, the authority to legislate, command and judge – even going so far as to state that “the prince [emperor] is not bound by the law”.  On this view, the will of the prince was held to be absolute; as the classical Roman jurist Ulpian famously put it: “what pleases the prince has force of law”.

Against the backdrop of the reformist institution-building efforts of the papacy, we can find 12th century canonists grafting these ideas onto pre-existing Christian understandings of episcopal authority to construct a specifically ecclesiastical notion of sovereignty: plenitudo potestatis or fullness of power.  Also known as plena potestas (full power) and libera potestas (unlimited power), this concept was used by canonists to convey the unique nature of the pope’s supreme ecclesiastical authority, his ability to promulgate new canon laws, his supreme judicial authority, and his role as pastor of the entire universal Church.

Under the influence of the canonist Hostiensis, further refinements were subsequently made to the idea of papal sovereignty over the Church, the most important of which was the introduction of the concept of potestas absoluta or absolute power. According to Hostiensis, potestas absoluta – significantly, deriving not from the corporate community of Christian believers, but from the pope’s authority as vicar of Christ – placed the pontiff above the law, much as classical Roman law deemed the emperor to be above the law.  Within the Church, at least, this meant that the pope enjoyed the kind of undivided and absolute sovereign authority that Bodin would theorize in connection with states several centuries later.

While the 14th century conciliar movement would later dissipate/dilute papal sovereignty to some degree, and while it would migrate into the temporal realm in a somewhat modified form, the concept of sovereignty – not modern sovereignty to be sure, but sovereignty nonetheless – was decisively re-introduced into European political thought and practice by the end of the twelfth century.

​​Based partly on these developments and partly on the continuing study and application of Roman law, from the 12th century onwards canon and civilian jurists also developed concepts of political sovereignty. According to classical Roman law, the emperor’s sovereignty encompassed all lesser kings, princes and magistrates. It is perhaps not surprising, then, to find pro-imperial political thinkers expressing similar claims regarding the emperor’s sovereignty in late medieval times.  As the medievalist John Watts has put it, “From the 1150s, [Emperor] Barbarossa and his heirs employed Roman law terminology and claimed the sovereign, and remarkably complete, legislative and judicial rights which the Roman people were thought to have handed over to their ruler.”

In the words of the German canonist Johannes Teutonicus, “the emperor is over all kings… for he is lord of the world [dominus mundi]… all things are in the power of the emperor”.  On this view, just as the emperor of ancient Rome had enjoyed imperium – i.e. the supreme authority to legislate, command and judge – so too did his later medieval “successor”, the Holy Roman Emperor.  In 1231 Frederick II promulgated a new imperial constitution, the Liber Augustulis, in which he formalized this claim to universal imperium.  Frederick asserted that as the successor to the Roman emperors of antiquity he had inherited the supreme temporal authority that his predecessors had originally received from the Roman people.  Whatever Frederick’s ability to give practical effect to this claim to imperium, it is clear that by the mid-thirteenth century at the latest the concept of temporal sovereignty had fully crystallized in the collective imagination of Latin Christendom.

While Roman law had explicitly vested full temporal sovereignty in the emperor, the political realities of late medieval Latin Christendom were such that other authorities could also claim to be sovereign.  As early as the 11th century, kings and princes had begun proclaiming their sovereignty by taking the title of emperor and adopting his attributes. These claims were recognized (to varying degrees) in the political practice of the era. Perhaps more importantly, though, they were also given increasing legal weight and precision in both canon and civil law.  In his famous decretal, Per venerabilem (1202), Pope Innocent III stated that the king of France recognized no superior in temporal affairs. Canon lawyers subsequently derived two doctrines of sovereignty form this claim. The first stated that the king was emperor in his own kingdom (rex in regno suo est imperator regni sui); the second that certain kings were sovereign in that they recognized no superior in temporal affairs (rex qui superiorem non recognoscit).

Significantly, 13th century canonists commenting on Per venerabilem disagreed as to whether it established de facto or de iure sovereignty.  For those subscribing to the former view, sovereignty was derived from and legitimated by the universal authority of the empire; for those holding the latter view, the empire was but one of many territorially limited sovereign states, and sovereignty was in no way derived from imperial sovereignty.

With the proclamation of Pope Clement V’s bull, Patoralis cura, in 1313, however, canonist thinking seems to have crystallized in favor of the de iure interpretation. Written to support Robert of Naples in his dispute with Emperor Henry VII over the sovereignty of the kingdom of Sicily, this bull definitively established the canon law precepts that the empire was a geographically limited state, that the emperor possessed sovereign authority only within that state, and that states beyond the empire were sovereign in law and without reference to the (non-existent) universal jurisdiction of the empire.

Differences between medieval and early modern sovereignty

Thus far, the account I have been developing has purposefully foregrounded the continuities between the late medieval and early modern norms of sovereignty. At this point it is necessary to cut against the grain of this argument and highlight some of the ways in which late medieval norm of sovereignty differed from it early modern counterpart – that is, to highlight its “medievalness”.  I would suggest that there were four such distinctively late medieval attributes or aspects of sovereignty.  First, late medieval states claimed and exercised sovereignty only with respect to temporal affairs, sharing sovereignty with the Church in spiritual matters.  Although there were “detailed differences of opinion on matters such as taxation of clerical possessions and the extent of the application of ecclesiastical jurisdiction,” the underlying norm – codified in law and reflected in jurisprudence and political thought – was that the clergy and laity constituted two distinct groups and that laymen could not make laws for the clergy. Indeed, while it is possible to point to thinkers like Marsilius of Padua who advocated the subordination of the clergy to the temporal authority, at no point did the norm of sovereignty include claims to a complete authority over ecclesiastical personnel or affairs.  Viewed against the backdrop of the doctrine of the Two Swords, it becomes clear that the spiritual sovereignty of the universal Church complicated late medieval sovereignty in ways that were unique to that era.

Second, in late medieval Latin Christendom, sovereignty was vested, not in a person (the “prince”), nor even in an office (the “crown”), but in the political-community-as-corporation (the “populus”).  In the early modern era, of course, one of the defining elements of the idea of sovereignty was that it inhered in the person of the prince. During the late medieval era, however, sovereign authority was part of the bundle of rights possessed by the fictive person of the political corporation.  It could be exercised by a prince, of course, but only in his capacity as embodiment of the immortal entity of the populus.  Early modern Absolutism, which vested unqualified sovereignty in the prince, was a post-medieval phenomena that the later medievals would neither have understood nor endorsed.

Third, and in a related vein, late medieval sovereignty entailed or connoted supreme, rather than absolute, temporal authority.  In practical terms, this meant that while the prince was the highest political authority within a given jurisdiction his power was neither unlimited nor unconstrained.  Among the constraints imposed on sovereignty were ius divinium, ius naturale, ius gentium, positive law, reason, custom, the nature of the office of the “crown”, and the rights of the governed, all of which placed historically specific limits on the sovereign will of the prince.  This is in marked contrast to the Absolutist monarchs of the early modern era who were seen as being above all law and custom and whose will (voluntas) was actually considered to constitute law.

Finally, quite unlike the modern state system, the late medieval society of states was organized in part at least around the principle of “sovereign inequality.”  By this, I mean that in the late Middle Ages there was no norm of automatic, reciprocal recognition of claims to sovereignty as there was in the modern era.  These had to be negotiated on a case-by-case basis.  And, as part of this dynamic, one type of state (the kingdom) was considered to be a more historical and/or natural locus of sovereignty than all the others.  In practice, this meant that kingdoms had the most legitimate claims to sovereignty and were therefore more likely to be recognized as sovereign states by other polities.  Principalities, communes, and leagues (the other types of state populating the system) were seen as legitimate claimants of sovereign authority, but somewhat less so than kingdoms. They thus had more difficulty securing the recognition of their claims to sovereignty and as a result were constantly exposed to the threat of absorption or subordination by top-layer authorities.

Andrew Latham is a professor of political science at Macalester College in Saint Paul, Minnesota. He is the author, most recently, of The Idea of Sovereignty At the Turn of the 14th Century. You can visit Andrew’s website at or follow Andrew on Twitter @aalatham 

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