The birth of modern warfare: war-making and state-making from a Western perspective

De Baripedia

The idea is to talk about what is sometimes called the paradigm of war-making and state-making, often equated with Charles Tilly, who considers that it is wartime activity that has contributed to the emergence of the State and that it is the State that has shaped a way of waging war leading to total war, such as the First and Second World Wars. We will focus on the historical conditions of the emergence of the modern state.

The State is not a universal mode of organization that has not always existed and does not exist everywhere, especially with failed States. The state has emerged in Europe with the demand for a monopoly on legitimate violence and on a specific territory. The State is also defined by its territoriality, by having a differentiated administration of the political society which is on its territory with an administration which, in principle, is independent and provides for the general interest in the public domain. The State has the capacity to define an autonomous political sphere in which its government can claim allegiances that are in principle exclusive to the population. One can think of empires or even the emerging states in the Middle Ages with populations that could have allegiances other than to their king as well as to the pope, an emperor, a local lord.

We will discuss the specificity of the State in relation to city-states and empires. The state is not the only form of political organization, despite what we tend to consider today. After the Westphalian treaties of 1648, states became the only model in international relations. Then, we will see how the modern state emerges from the Middle Ages and what are the specific conditions for the emergence of the modern state. Finally, we will discuss Charles Tilly's paradigm of war-making and state-making, which shows how war has shaped the state and how wartime activity has contributed to the special conditions in Europe allowing the emergence of the state.

How did the modern state and thus the modern warfare that it is shaping in its image emerge? The period before the late Middle Ages, which is the end of antiquity, was marked by the Roman Empire which saw itself as the most successful political construction, organizing the two coasts of the Mediterranean around Rome and bringing the "pax romana". The Roman Empire had many flaws and shortcomings that will partly explain its decadence and its end, which will allow it to create the conditions from which a new form of hierarchical and organized political organization will lead to the modern state. The modern state, even if in principle it covers a territory smaller than the empires in organisational and military terms, will prove to be much more efficient than the empires that preceded it. However, it is its destruction that will create the conditions for the particular political form of the modern state to emerge in Europe. How? How?

States, City-States and Empires[modifier | modifier le wikicode]

We tend to use these terms interchangeably. We think that a city-state is going to be smaller than a state, that the empire is going to be bigger. Historically, these are more precise and different truths. In On the medieval origins of the Modern State published in 1970, Joseph Strayer shows that the state as we think it did not always exist and that if it became dominant at any given time, it was not necessarily inevitable. These are special conditions that make us think the state we think today has become the only dominant and recognized form of international law. It shows that in the Middle Ages, there were two forms of political organizations that could compete with the state.

According to Strayer, the modern or national state, which should not be confused with the nation-state, is beginning to emerge between the 11th and 13th centuries. The state ends up according to Max Weber's definition as claiming the monopoly of legitimate violence in a given territory. But the game is not played in advance: there are still two types of political entities that can compete with nascent states, namely empires and city-states. The question arises as to what characterizes these two forms of political organization, what characterizes the modern state and how empires and city-states can be defined in relation to the Weberian definition.

Empires[modifier | modifier le wikicode]

The Consummation of Empire. Oil on canvas, 1836, 51 × 76 in.[7][8]

The empire refers to a military notion. The word comes from the Latin "imperium" referring to the power and authority of the military leader. The empire was built by military power, conquest and expansionism. This term of "imperialism" where the "empire" is above all a military power before being a political power. The idea of empire is linked to the idea of infinite spatial expansion. One can imagine the empire as a political entity based on military force tending to extend as far as it is allowed to do so given the military balance of power. According to Max Weber, the state is characterized by the territoriality of an empire that extends as far as possible. If one state is in a region where all other states are weak, it will do the same. When there is an imbalance of power, the States, despite their territoriality, did not hesitate to launch expansionist policies, especially with the phenomenon of colonization where the State extends its empire. Infinite expansionism is in principle impossible, which makes the state and inter-state character within the international system in which it is developing.

This has three implications:

  • The empire does not recognize "sovereign equality": its only way of recognizing foreign groups is through incorporation. In international law, what characterizes relations between States is the principle of sovereign equality. The empire does not have a foreign policy, foreign policy and diplomacy as we think and conceptualize it today precisely because the objective of the empire and its practice is to extend to infinity. What lies outside the empire is considered as uncivilized or with a vocation to integrate into the empire.

The empire has no borders, only steps: it ideally extends its power throughout the "known" world, there is no discreet space. The steps of the empire are an area where authority declines further away from this capital. Today, some postulate that Russia maintains an imperial policy with seemingly blurred external borders. For an empire, there are concentric circles and the farther away from the center of these circles the less the influence is strong.

  • The empire does not assimilate the populations it incorporates and does not necessarily question pre-existing political forms as long as they fulfil military and economic obligations.
  • If a political entity is simply based on infinite military expansionism, it is certain that it will certainly not have the time or the administrative capacity to work on assimilating its populations so that there will be cultural homogenization. There will not be an autumn political sphere in which a state can claim exclusive allegiance from its people. Empires tend to be extremely heterogeneous with populations associated with the empire and incorporated while claiming a different political authority, but which the empire tolerates as long as it is not powerful enough to subjugate them.
  • double principle of incorporation and differentiation: according to the historian of empires Frederick Cooper, empires are based on incorporation, but at the same time on a principle of differentiation since within the empire the difference between Latin and Germanic peoples is maintained for the Roman Empire, Chinese and Mongolian for the Chinese Empire. There is a differentiation between different categories of populations. In the colonies, colonial subjects have a different status from the national population, it is not because they are incorporated that they are assimilated. Historically, states have pursued policies of territorial annexation.

The Chinese Empire saw itself as the Middle Kingdom, and the further away from the center and the further away from that middle of the world, the less authority the Chinese emperor had. Empires consider that the outside of the empire is the "uncivilized" world in which it is destined to expand. This is true of the Roman Empire, but also of all empires. They are based on a universalism which considers that in principle the world must be unified under the authority of the empire and that it is impossible for an empire to recognize other empires. The Holy Roman Empire had the ambition to unify Europe and the world, especially if the emperor managed to become the head of Christianity, which holds authority over the whole of humanity to be Christianised. When it is said that there are entities incorporated into the empire, it refers to the exclusive allegiance to a central government and the monopoly of legitimate violence, that is to say that the local kingdoms and chiefs incorporated into the Empire remain the owners of their arms and armies and use force on the territories they control what is tolerated by the empire provided that this does not come

At the time, the main source of wealth and control of territories that it is possible to cultivate. To exert an imperium on ever-increasing territories means having more and more wealth. Empires have no outside rivals and if they do, they incorporate them. Empires live in relative self-sufficiency. It is also necessary to understand that their military and economic power and function of the spatial extent of its territories that it controls. The more territories are incorporated into the empire, the more tax and military obligations there are. This creates military power and economy that feeds the machine of expansionism that is the empire with the weakness that by incorporating and maintaining differentiations, the empire is weak internally and strong externally. Internally, there are still royalties, chiefs and tribes that can turn against the emperor. There are often internal wars, splits, and hence the absence of a legitimate monopoly.

Cities-States[modifier | modifier le wikicode]

The city-states are kingdoms, republics or democracies at the level of a city. The originality lies in the fact that the city-state is a political unity at the level of a city. The city-state has no hinterland and hinterland without economic autonomy in terms of subsistence needs. The subsistence goods of agricultural origin come from abroad, hence the fact that city-states are based on trade. They are political units not based on imperialism, but on commercial power. The state city is a small political unit with an urban character, strong integration and weak cultural differentiation. All free male citizens shared a common language, a common culture that is a form of proximity. There was a strong cohesion based on intercohesion within the city distinguishing the city-state from the more disparate empire. In the city-state, they are people with weak cultural differentiation sharing the same culture, highly integrated.

City-states are often linked to a commercial function and capital accumulation at the crossroads of trade routes, markets or ports. The strength of the city-state is its cohesion and its weakness is its small size, but also its lack of autonomy for its subsistence since the city-state is cut off from the hinterland. Modern states, unlike city-states, manage to create the same sense of cohesion, but in a territory much larger than that of a city.

Strengths and Weaknesses of Empires, Cities-States and States[modifier | modifier le wikicode]

Strengths Weaknesses
Empires - Size-related power (extensive model)
- Low external competition
Internal divisions, administrative weakness, internal wars, weak integration, "Imperial overstretch".
Cities-States Strong policitcal cohesion and integration Small size = risk of incorporation by more powerful entities, economic dependence on the "Hinterland", no "granary".

Empires and city-states are opposed to each other. This will enable the modern state to exist by combining the strengths of these two models while avoiding their weaknesses.

The State combines the "strengths" of both models, avoiding their "weaknesses"[modifier | modifier le wikicode]

The state as defined by Max Weber is marked by integration and relatively strong cohesion based on nationalism, political allegiance at the centre. In a modern state, in principle, there is not only one city, but several cities, rural and rural populations. Despite the diversity of cities and rural populations, the State will succeed in creating the same situation as a city-state, but on a broader and more diversified scale. There is political homogenization and political participation that are organized around the federal or central government. It is a political allegiance in principle exclusive with national cohesion within the so-called "modern state".

At the same time, the modern state manages to extract military and economic resources from its population. It is an intensive model of extracting military and economic resources through a centralized administration without the need for infinite expansion. It is the intensity of resource extraction from the population that characterizes the modern state. The transformation of the state as a war from state to "nation into weapon" is something that only a modern state can do, empires were incapable of doing.

These two elements reinforce each other. If we impose extremely high taxes and increase the military obligations of a population that otherwise has no particular allegiance to the central government, we will create a state of civil war or even separatist and secessionist entities, if this model of extracting the population is possible, it is not only if there is a centralised and organised model, but also because there is strong cohesion, cohesion and solidarity.

The fact that the modern state combines the strengths of the two models shows that the state is linked to elimination struggles between political entities. When there are wars between an empire and city-states, there is good reason to believe that city-states will be incorporated into the empire unless the empire divides internally. When there are modern states present, these states incorporate cities and destroy empires because they have the strength and not the weaknesses. The state will be created by war and impose itself through war to eventually become the dominant model in Europe. Elias emphasizes the extent to which the idealtypical state is linked to playoff struggles between political entities.

To understand how struggles will lead to the creation of modern states, we must go back to the late antiquity and early Middle Ages.

Conditions for the emergence of the State in the Middle Ages[modifier | modifier le wikicode]

The fall of the Roman Empire[modifier | modifier le wikicode]

Roman empire at is heigh 1.jpg

Classical antiquity is characterized by a relatively high degree of political and military organization in comparison with the previous and succeeding period. The fall of the Western Roman Empire in the year 476 will see a partial triumph of the Germanic tradition of "armed bands" and the "Faid" / "feud". Where there was the extensive Roman Empire that managed to politically organize most of the European continent and militarily efficient, with the fall of the Roman Empire, there will be a total fragmentation of the territory of the former Roman Empire, which will see much smaller political units emerge and clash in the former territories of the Roman Empire.

Empire romain invasion barbares 1.jpg

The modern state as an effective administrative and bureaucratic apparatus will emerge. This emergence would not have been possible if the Roman Empire had endured because an empire is characterized by the fact that it incorporates without external competitor, this does not force it to centralize, to impose the monopoly of legitimate violence. An empire, as long as it is an empire, has no external competitor so it does not need to strengthen itself internally, for example by extracting more economic resources or increasing military obligations because it has no external enemy.

This will stop with the fall of the Roman Empire with kingdoms that will clash to reconstitute the Roman Empire. It is in this confrontation that, in order to survive in the political competition between kingdoms and tribes on the same territory, these political entities will gradually be led to extract more and more taxes and military resources, since it is only on this condition that these political entities can survive and see the emergence of modern states.

The origins of feudalism[modifier | modifier le wikicode]

The system that will emerge with the fall of the Roman Empire will no longer be based on an imperial principle but on a feudal principle. It is a system in which political and military power is fragmented across the European continent. There will be bitter political and military competition between these scattered political and military units in which each kingdom will have an interest to strengthen itself internally, in particular by creating an efficient administration to collect taxes and an army. As time goes by, an ever-growing administration will be created to pay staff and raise even more taxes. A self-sustaining process will be set up whereby the war machines of the military kingdoms and aristocrats will constitute a monopoly of violence in a given territory. The paradox of the modern state is that it will end up much more centralized, efficient and militarily powerful than the empires of yesteryear. The fall of the Roman Empire was seen as a period of regression. The Roman Empire is seen as the most advanced form of political authority and feudalism would be a mode of regression, but this regression, disorganization and dispersal of power will create a new political model that is the modern state that will define more centralized, hierarchical and effective than the Western Roman Empire.

The Middle Age is considered to begin with the fall of the Roman Empire. During this period, there were permanent attempts to recreate the Roman Empire through "centralization", but fragmentation prevailed in Western Europe. A multitude of kings will try to restore the empire. The principle of lost unity will be an element of fragmentation rather than unity. The feudal system emerged after the fall of Charlemagne's empire in the 9th century as a political and above all military system combining on the one hand the fusion of the feud and the public office referring to the Roman heritage, and on the other hand the vassalic principle referring to the Germanic heritage. On the almost continental scale of Europe, a feudal order was to be established which attempted to restore the Roman Empire, but assumed fragmentation.

Feudal system[modifier | modifier le wikicode]

Feudal pyramid 1.png

The feudal system is based on the exchange between a monarch who controls territories, but has no army and military aristocracies who have weapons and the ability to wage war, but whose territories are given by the king. It is from this principle that the feudal system will emerge. A feudal system based on the distinction between suzerains and vassals. The suzerain needs protection and military resources, for this he will enter into contractual relations with vassals who are warlords who need territory. The suzerain will then give a fief to the vassal that he will be able to control in exchange for which the vassal will have military obligations to protect the suzerain when attacked from the outside.

What creates a vertical relationship is the need for land, which refers to a principle of land distribution in exchange for military obligations to the higher level. As territories are redistributed from suzerains to vassal and subvassal, fiefdoms become fragmented. There is a principle of fragmentation and territorial division. It also means that the ability of the king and vassals to wage war depends on the fluctuating allegiance of their vassals. In reality, each vassal and knight is in some way autonomous so that if his suzerain is threatened, he may be lacking even if it breaks the feudal bond. Quite often a vassal often has several fiefdoms bequeathed by different suzerains. The higher levels and especially the king are never certain of his military power. There is no monopoly on the king's legitimate violence, but a principle of dispersal of the territory divided into fiefdoms, but also into military units divided into multiple chivalries that characterize the Middle Ages.

Politically, the feudal system is a fragmented, multiple system, with multiple allegiances, changing and overlapping, it is a dispersed power. From a military point of view it is a system of knights rather than phalanxes based on a multiplicity of soldiers creating compact military units and mutual solidarity. The feudal system values the individual prowess leading to an individualization of war in a system of allegiance, but they are more distant than those of the phalanx and much more random. Ultimately, war remains a matter of personal and individual estimation in the choice of allegiance. There is a blurring of war and personal revenge.

Faid "refers to revenge and vendetta between families. Revenge is called "Werra" in Germanic which will be Latinized in "Gwerra" then will be declined in "War" and "war". The term war finds its source between these feudal struggles between feudal lords in the Middle Ages. It is a metaphor that it is these struggles and the climate of competition between knights, lords and kings on the European continent that the modern state will emerge. It is therefore a politico-military system based on "decentralization", but which maintains a limited war power in the hands of the king.

France under Hugues Capet in the 10th century[modifier | modifier le wikicode]

France sous Hugues Capet au Xème siècle 1.png

France is divided into different territories with the royal estate around Paris. All the other territories of the Kingdom of France were bequeathed to other lords, who themselves bequeathed them to their vassals. The territory that belongs to the king is small in comparison with the Kingdom of France, which is itself controlled by different lords. The king has very little control over his kingdom, showing how fragmented the territory is and how much there is no monopoly on legitimate violence, and therefore there is no modern state by far absent. There are very complex networks of military obligations between these Dukes, Count and the King.

These kingdoms of Europe are fragmented systems between nobles, different kings on the scale of the European continent, but also between kings and their vassals. In the end, the king is only one of many lords. A process will begin which, by the very dynamics of this competition, will gradually create the modern state as analyzed by Charles Tilly in his book Coercion, Capital, and European States. He explains that this feudal system will lead to the emergence of political units that are more and more centralized, bureaucratically efficient and that will eventually succeed in monopolizing legitimate violence over a relatively large territory.

War-making/State-making[modifier | modifier le wikicode]

This is not an intentional process[modifier | modifier le wikicode]

It is not an intentional process, but something that will result from a struggle:

  • Internal competition "within the Kingdoms between lords for the land: increasingly large spaces concentrated in the hands of fewer and fewer lords in" playoff battles ". For Norbert Elias, when there is competition between different units that are indistinguishable, there is a strong chance that progressively the weakest units will be eliminated, but a monopoly will gradually emerge. When we talk about competition and competition in a territory, no one can prevent the most powerful lords in the feudal system from defeating the less powerful lords until only the most powerful lords remain until they reach a monopoly. Elias explains how gradually the king will emerge as the most powerful lord on a territory. There is an internal competition and progressively in a military struggle, more spaces will be concentrated until there is only one lord left who will impose a monopoly of legitimate violence by means of struggles of interest through the monopoly principle.
  • The monarchs want to unify the Christian world, but without having the spiritual resources because it is the Pope who holds them. This competition therefore involves warfare and requires the extraction of resources and therefore administrative capacity. Whenever one state or kingdom centralizes and bureaucratizes a little more than another, it becomes militarily more powerful and more dangerous for other kingdoms to do the same. For example, the French Revolution is a regime overthrow that goes hand in hand with a movement to centralize the French state. In 1793, a mass survey took place in which the entire French population was mobilized against the outside powers. All European states will have to do the same or they will be overthrown by France. Napoleon's victories forced the other European states to centralize and stir up nationalism. In inter-state competition will be forced to do the same states. There is going to be a competition that goes through war, forcing each state to strengthen itself by making resource extraction from its own population more efficient.
  • These administrations allow the monarch to strengthen his power over the lords, but do not exempt him from negotiating their participation in wars: According to Tilly in Coercion, Capital, and European States, AD 990-1990 published in 1990, using both internal competition even to the pre-eminence of a single sovereign and competition between kings on the European continent through strategic interdependencies will lead to state centralization that will ultimately lead to the creation of the modern state. In the United Kingdom, this negotiation gave rise to the Magna Carta in 1215 which is a document by which the English aristocrats agreed to support the wars led by the King of England John without Land, in return, the king must allow a certain political representation to the aristocracy and therefore the feudal lords. The principle of Magna Carta is "no taxes without representation". Aristocrats support the king provided they can participate in political positions on peace and war. This is the historical origin of parliamentarianism. The principle of negotiation between monarchs on the one hand and feudal lords on the other will see the establishment of a compromise based on parliamentary democracy at the end of a long process. The monarch has an obligation to negotiate with the military aristocracy which, because of fragmentation, obliges it to limit its power in order to obtain financial and military support from its vassals. The French Revolution is both a process of centralization and democratization.

France under Louis XI: 1423 - 1483[modifier | modifier le wikicode]

Unlike Hugues Capet's France, the royal estate was gradually to be gradually extended to include the fiefdoms of other lords. The royal territory is extended well beyond the Île-de-France until the unification of the kingdom of France, which establishes a fiscal, administrative and military monopoly by the State, i.e. the monarch on the whole territory.

France sous Louis XI.jpg

War-Making/ State-Making[modifier | modifier le wikicode]

The accumulation of territories in the "royal domain" will generate internal elimination struggles, but it is also an external struggle that will force each of the kings to centralize power internally, to concentrate resources in the royal administrations that become more distinct from the king's person. Under feudalism, the king is the "primus inter pares". The king's power was related to his personal property. As the state centralizes, concentrates more and more power, power and financial resources, sets up more and more efficient administrations, monopolizes armies, the king's power begins to differ from the person of the king. What was the king's personal fortune will become the state budget. The political system that prevailed in the kingdoms of the Middle Ages was a heritage system. A patrimonial power is a power for those whose political resources are their private property. What characterizes the patrimonialist power is that the King's resources as a political leader are the private property of this political leader. As the state strengthens, centralizes and the modern state emerges, power will become less and less patrimonialist leading to a distinction between private and public persons with the king as person and the king as crown. Emerges the mystical theory that the king has two bodies, a physical body and a symbolic body. As the power becomes more centralized and strengthened, it differs from the person of the king whose personal powers will thus be limited.

The power of legitimate violence is worthless without a monopoly on fiscal violence. In a modern state, not only can the government decide whether to use force and be able to raise taxes in opposition to what prevailed during the feudal period. For Charles Tilly,"War makes the State and the State makes the War" characterizing the historical trajectory of Western Europe, which closely links the construction of war to the power of the State.

The first paradox is that the feudal kingdoms of the West will become more centralized than the empires of Central and Eastern Europe. Byzantium, which was inherited from the Eastern Roman Empire and then from the Ottoman Empire, wanted to embody the principles of the Roman Empire with the principle of unification of one continent or even more and a strong organization much more so than was the feudal systems. Gradually, these feudal monarchies will become more centralized, more effective militarily and politically. This marks the victory of modern states over empires that failed to survive the elimination struggle.

The second paradox is the fact that, according to Michael Mann, the king as "despotic power" is declining even as "infrastructure power" increases. It is the power of the state as a public entity separate from the person of the king to change and reform society internally. States decided in the 19th century to homogenize national culture and language. The modern state has been able to impose cultural, linguistic and legal homogenization on its entire political society. The modern state is much more powerful from the point of view of infrastructure power, but at the same time the despotic power of the executive is much less important in modern states.

From the "Holy Roman Roman Empire" (962 - 1806) to the Prussian Garrison State and Germany[modifier | modifier le wikicode]

The Holy Roman Empire which is one of the heirs of the Roman Empire with a will of the Emperor to recreate an Empire based on Christianity is made difficult because of a strong internal competition and a strong external competition which will lead to a concentration of power, to an accumulation of political power which will lead to the emergence of Germany. It is not the emperor that will prevail, but it is a principality within this empire which is Prussia that will unify the territories and create modern Germany from a centralization and accumulation not in the hands of the Emperor, but through the kingdom of Prussia. What is important in this process of constructing European states through war making/state making is that we will end up with a monopoly on legitimate violence in a given territory.

Pacifying the interior: Norbert Elias[modifier | modifier le wikicode]

Gradually, the power of the executive branch has the ability to wage increasingly powerful wars internally and externally. The monopoly of internal and external violence also means that society as a whole, its elites and especially the aristocrats, lose the ability to use private violence. Internally, according to Elias, there is internal pacification with less and less violence on the national territory. This internal pacification is linked to the pacification of the State because monopolizing legitimate violence deprives the use of private violence leading to a development of self-control, self-discipline and restraint in morals. Muchembled notes a decline in interpersonal violence since the 17th century.

Le duel à l'épée, par Jacques Callot, 1617[9]

Traditional monarchies in the Middle Age had no police. The modern state invents the police, which has the characteristic of using less violence with a culture of minimal force in the idea of using force as a last resort on a proportional basis. This comes at a time when the state itself is becoming increasingly violent and trying to pacify the population. This is a time that confirms and reinforces the long-term trend of pacification of European societies. However, political modernity also coincides with genocides and wars of annihilation, hence the schizophrenic dimension of the modern state.

Louis XIII forbids duels in 1626. As warlords lose the ability to wage private wars, this is known as the curialization of warriors. They will gradually transform their practice of violence in order to put them in shape, no longer to wage private wars, but at the same time to use violence to defend their honour through the practice of duel. Duels are in a sense what remains of the traditional power of aristocrats to wage private wars without recourse to the king. The prohibition of the duel symbolizes that from 1626 onwards, the king intended to have an absolute monopoly on all forms of legitimate violence and all forms that could be exercised by individuals. This decision may seem anecdotal, but at the same time it symbolizes the creation of the state and the emergence of the monopoly of legitimate violence by withdrawing the right to use interpersonal violence.

Conclusion[modifier | modifier le wikicode]

The increased extraction of military resources through taxes and recruits in the service of war requires increased bureaucratization. Increased bureaucratization requires and allows for an increasingly unbridled extraction of resources and the conduct of increasingly deadly wars. Their interaction in a "proto-international" system that prevails in Europe under the feudal system and during the Renaissance in which no kingdom can become stronger than any other, contributes to the emergence of the Weberian state.

Notes[modifier | modifier le wikicode]

Bibliography[modifier | modifier le wikicode]

References[modifier | modifier le wikicode]

  1. [Davidshofer | University of Geneva] -
  2. Publications de Stephan Davidshofer |
  3. Davidshofer, Stephan. “La Gestion De Crise Européenne Ou Quand L'Europe Rencontre La Sécurité : Modalités Pratiques Et Symboliques D'une Autonomisation.” Http://, Paris, Institut D'études Politiques, 1 Jan. 2009
  4. Page personnelle de Christian Olsson sur le site de l'Université Libre de Bruxelles
  5. Page de Christian Olsson sur
  6. Profile Linkedin de Christian Olsson
  7. "The Course of Empire: The Consummation of Empire". ExploreThomasCole. Retrieved 20 March 2011. 
  8. "The Paintings". Beyond the Notes: The Course of Empire. Retrieved 23 October 2014. 
  9. En garde ! Les duels dans Gallica | Gallica, (2015). En garde ! Les duels dans Gallica | Gallica. [online] Available at: [Accessed 17 Feb. 2015].