The Legality of Noble Warfare

by His Lordship Friar Thomas Bacon (David Moreno)
Orignally published in the June and July 2006, A.S. XLI issue of the Dragonflyre, a publication of the Barony of Vatavia.

Warfare was a constant feature throughout the Middle Ages, perpetrated at all levels of scale. Fighting was the profession of the nobles, and they were happiest when engaging in it. Plunder was one of their main sources of income. A long peace would reduced many of the lesser nobles to poverty. As the armored knight was virtually immune from retribution from the ordinary populace, he often pillaged at will. But as the period progressed, an effort was made to regulate this strife. This paper will deal with one aspect of this effort: the legitimacy of hostilities.

Like much else in the Middle Ages, there are two major viewpoints on this issue; the secular and the ecclesiastical. The secular viewpoint centered on the oath of fealty, and involved such questions as when may a vassal refuse to come to the aid of his lord, or rebel against him. The church viewed war as an undesirable fact of life. Thus it sought to restrain who could declare war, and limit when it could be declared. In short, it tried to define the "just" war.

The first person to deal with this topic, and set the parameters of the discussion, was St. Augustine of Hippo. St. Augustine's initial problem was to reconcile the pacifistic nature of the Christian church with the notion of war. He did this by separating the intention from the act. To kill one's enemy was both a punishment and an act of charity, preventing him from committing further acts of evil. The evil of war was not war itself, but the malice, hatred, and the love of violence and cruelty that normally when with it. The goal of war was peace.

Having justified the existence of war, St. Augustine then defined when war was justified. For this, he relied mostly on Roman law, the Empire still very much in existence in the time of his life. The central idea comes from Cicero, and remained the touchstone for all medieval discussion: just wars avenge injuries. What is meant by this phrase is that the objective of war is to restore the status quo, or to render justice.

Of course, this loose definition is open to wide variations of interpretation. It also leaves open the questions of proper authority, conduct, and sufficient provocation for war. It was to these questions that the remainder of clerical discussion turned.

On the question of authority, St. Augustine left it in the hands of the kings. While the Western Empire was in the advance stages of decline, Roman legal institutions were still active. And this simplistic answer was adequate.

As for the conduct of war, St. Augustine's surprising answer was that anything was permissible. The reasoning behind this is that St. Augustine's concept of justice incorporates the concept of righteousness. That is, inflicting injury is not only a crime, but also a sin. Therefore, the unjust party has placed themselves outside the moral sphere of restraint. This aspect of justice can lead into the area of religious war, which is outside the scope of this paper.

The reasons that a king may have used to declare war were two. First was to recover property that had been taken. Second was to redress the infringements on the rights of the aggrieved party. St. Augustine also considered divine command just cause for war. This is the takeoff point for the legality of the crusades, a topic again outside this paper.

As the Empire disintegrated, violence became epidemic. Clerical thought turned to reducing the overall level of mayhem, and the concept of just war was not furthered. In fact, during this period, anything military was considered suspect. Year long penances were imposed, even for a just war. But in time, as things began to settle down, the topic of just war was picked up again, this time by a monk named Gratian in the first systematic compilation of cannon (church) law; the Concordia Discordantium Cannnum, or Decretum.

I must first, briefly, talk about the nature of medieval scholarship. Up until the time of the Renaissance, ideas were judged primarily by the their age and attribution. Thus a saying by an early church father held more weight then that of ninth century commentator, while that of a contemporary held none at all. To suggest that one of these hoary authorities could be wrong was unheard-of. The innovation of Scholasticism was to collect all the previous writings on a given topic, and then thread a compromise that tied them altogether. The form by which this was done was to pose a question, then present all the quotations that supported one side, then all the quotations for the other side, then the author's commentary and conclusion.

The relevant section in Gratian's Decretum is question (Causa) 23. Since St. Augustine was still the only comprehensive writer on this subject, his influence is widely felt in Gratian's writing. Indeed, Gratian amplified and expanded on St. Augustine's work. His section on the moral acceptability of war, based on St. Augustine's concept of charity, was so convincing that it virtually ended discussion on the point.

Gratian enumerated four causes for a just war: to repel invasion, to recover property, to avenge prior injuries, and denial of legal rights. The third cause involves the offending party not punishing his subjects for their misdeeds. The usual example given for the last cause is the denial of free passage across foreign territory as evidenced in the Bible (the authority par excellence) in the Israeli war on the Amorites (Numbers 21: 21-5).

The prime aspect of war in Gratian's analysis is that it is an extraordinary extension of the judicial procedure. That is, if you can't get satisfaction in court, go to war. To prevent this from countenancing private war, Gratian emphasizes that proper authority was necessary to wage war. To Gratian, this meant public officials, whom were assumed to be dispassionate judges and executioners. However, in the then current chaos of feudal public government, this meant little.

The canon lawyers who followed Gratian were called Decretists from their method of commenting or glossing the Decretum. Their contributions to the discussion were the terms "ordinaria potestas" and "potestas principis"; that the person declaring war should have sufficient authority. While still inadequate, it pointed to the idea that only those with higher jurisdiction could engage in war.

It was the next generation of lawyers that defined the final position of the church on war. These were the Decretalists, so called from their method of glossing the papal decretals, the church's version of legislation.

The Decretalists defined five criteria to judge whether a given military action was a just war. They were "persona", "res", "causa", "animus", and "auctoritas". The first term involves that state of the person campaigning; that he was to be a laymen. Clerics were prohibited from fighting, though bishops who were temporal authorities were usually given permission to command armed forces. The second term refers to the objective of the war , which was to either recover property, or to defend the patria, or homeland. The third requires that the immediate circumstances necessitate the war, i.e. hostilities have already commenced. The fourth criteria judged the intentions of the belligerent: that their intent was not to punish, but included piety and justice and forswore hatred and cruelty. The last is proper authority, in this case princely authority.

The Decretalists also identified seven types of war. The first was the Roman war of the faithful against the infidels, so called because Rome was the head of the Christian faith. The second is the Judicial war, waged on the judicial authority of someone possessing "merum imperium", disinterestedly enforcing judicial order. These two were considered just. The third type of war, which was unjust, was resistance to the enforcement of judicial order being imposed by the war of the second type. The fourth variant was a war to repel injuries to one's associates, to be conducted by those with proper authority. The fifth form was the unjust opposition to the last named. The sixth was the unjust war based on personal authority. The last was the war of self-defense against the attackers of the previous war.

The Decretalists settled the question of authority, when they declared that except in cases of self-defense, only those who had no superior had full rights to wage war. These rights were constrained not only by the fact that the cause had to be just, but that all other legal recourse had been exhausted. As long as the other party was willing to submit to judgment, war could not be waged against him.

The polishing touches to the theory of just war was done by St. Thomas Aquinas. Up until this point, medieval theologians, having no special point of reference, had but followed the canon lawyers. Aquinas' contribution was the integration of Aristotelian thought with the current body of theory; in particular, Aristole's concept of common good.

Shortly afterward, the church's edifice of the just war crumpled as papal moral authority evaporated. As the secular monarchies came to the fore, they subsumed the just war theories into their own theories of national sovereignty. In addition, the changing face of war removed the validity of their underlying assumptions. While the formulations of the theory continued to be used, there was no longer any life in them.

While the church generated a large corpus on the subject of just war, the secular writings are rather meager. Part of this, of course, is result of the intellectuals of the time gravitating to the church. The other part was that secular jurisprudence was based on custom and usage, adjusting to the circumstances at hand. Thus, an overarching theory of law and justice was lacking.

There was two main sources of secular law. The first was the customary law of the barbarians tribes that overran the Roman Empire. While it deals extensively with vengeance, a form of private war, there is no concept of war as a public effort. The second source was Roman, particularly in the form of the "Digest" of Justianian, a compilation of all Roman laws, decrees, and judgments up till that time.

The basis of just war in Roman law is centered on self-defense. Moreover, the concept of war ("bellum") was restricted to declared enemies. Military action against others was termed "guerra", and they were known as just robbers and brigands. The key difference between these two forms of hostilities is the treatment of captives. Those taken during the course of bellum, were capable of regaining their rights of citizenship at the end of hostilities. Those taken in a guerra became ordinary slaves. The major weakness in these formulations was that the only person with the power to declare bellum was the Emperor, a point sadly out of touch with feudal Europe.

In the everyday world of the secular courts, there was no conscious theory of just war until the 14th century when the emerging central monarchies took the church developed efforts and made them their own. Nevertheless, there arose a vague notion of what would be permissible warfare. This developed around the feudal concepts of homage and vassalage.

The key legal aspect of homage is the personal contract between the lord and the vassal. If the vassal failed to hold up his end of the contract, the lord was permitted to take up arms against him to enforce that contract, or to regain the fief that he had given to that vassal. If the lord failed to uphold his part, the vassal was then free to defy the lord, and take up arms in self-defense.

Of course it did not work out so simply or absolutely in practice. There was the ever present question of whether the lord had the military power to enforce his will. Also complicating matters was since around 1000AD most fief were considered hereditary, and thus not easily required by their lord. Since in feudal theory all power flowed from the king, it was eventually the king who came to dominate the judicial landscape.

Among key powers of feudal government were the rights of justice. Much of the central monarchies' growth of power came as the kings encouraged disputes to be settled in their courts. While this effort did not expressly prohibit fighting among the nobles, it was clearly in the king's interest to maintain the peace. Louis IX, also known as St. Louis, set out a complicated set of rules to make war among his vassals as difficult as possible. You had to give your foe notice before attacking, as well as inquire among his relatives to see if they wish to be included. You had to grant a truce, if requested. And you could not burn his crops or kill his peasants. Philip IV (the Fair) went so far as to outlaw private war or to ride out armed, but this was repealed after his death.

And yet rebellions and disorders were commonplace throughout the period. But the defiance was always couched in terms of a breach in the feudal bond. A firm belief of the time was that if there was no justice, there could be no authority. The baronial revolt against King John of England revolved around John's abuse of feudal privileges as outlined in the Magna Carta. And a key provision of the charter codified the baron's right to take up arms against the king.

Perhaps the best known internoble conflict is the War of the Roses. While the central dispute was the dynastic struggle over the throne of England, it served as a cover to settle many noble rivalries. Indeed, which side a noble family would support depended as on kinship, friendship, and marriage as much as, if not more so, the political claims being advanced. The worst excesses occurred when the monarchy was at its' weakest. And yet all this lawlessness was always done in the name of some claimant of the throne. The idea that the nobles could act on their own had long since disappeared.

Thus ends my review of the legal underpinnings of warfare in the Middle Ages. Of the two legal traditions, the church had the more comprehensive view, but had only minor impact in the field. did customary law, for the feudal compact was too loosely defined, and allowed many excuses to engage in war. It was only with the decline of feudalism, and the rise of the central monarchies that permitted the regularization of warfare into the hands of the king.



Bloch, Marc. Feudal Society, Vol. 1 & 2. Trans. L. A. Manyon. Chicago: University of Chicago Press, 1961.

Painter, Sidney. French Chivalry Ithaca: Cornell University Press, 1940.

Painter, Sidney. The Rise of the Feudal Monarchies Ithaca: Cornell University Press, 1951.

Ross, Charles. The Wars of the Roses : A Concise History. London: Thames & Hudson, 1976.

Russell, Frederick H. The Just War in the Middle Ages. Cambridge: Cambridge University Press, 1975.

Sources of English Constitutional History: A Selection of Documents from A.D.600 to the Present. Ed. and trans. by Carl Stephenson and Frederick George Marcham. New York: Harper & Row, 1937.

Zacour, Norman. An Introduction to Medieval Institutions. New York: St. Martinís Press, 1976.


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