In autumn 1900, the German colonial officer Robert von Krieg was travelling in the deep interior of what was then the colony of German East Africa. At Rubugwa, in the district of Tabora, his expedition of askari soldiers and porters must have been rather astonished to come upon a group of camping uniformed colonial soldiers, so-called “Sudanese,” who declared they had come from British territory. It is highly probable these men had come from British Uganda, where Sudanese soldiers in British service had mutinied in 1897 and had turned their weapons on the colonisers in what turned into a fierce war and an ensuing hunt for the remaining groups of mutineers, which lasted over two years. We do not know whether the German officers were aware of this history when they encountered the 30 Sudanese hundreds of kilometres from the Ugandan border, though the Germans probably were. Either way, they did not concern themselves greatly with these details. As Von Krieg’s diary reports rather matter-of-factly, the Sudanese simply entered German service.
This case, of how ‘mutineers’ from one empire with one swoop simply became the colonial soldiers of another is just one example of how actors of fin-de-siècle colonial violence, and with them their knowledge and experience, crossed the borders of different empires. It points to a transimperial history of colonial war and violence around 1900 that, by and large, we cannot yet find in the historical scholarship. On the most basic level, it is clear that few phenomena were probably more common to empires than colonial war and violence. Colonialism everywhere was established by violence and armed force, and was everywhere ultimately maintained by it. Yet, to view colonial war and violence as a transimperial phenomenon requires more than this simple diagnosis. It means to study the phenomenon across imperial (and often thus also linguistic) boundaries, drawing comparisons and, in order to make it a truly transimperial history, identifying the connections that existed between empires when it came to the employment of force against colonised populations. This is what this short essay attempts to do; moreover, it seeks to go one step further and trace the origins and driving forces of such connections.
So far, relatively little has been done in the way of a transimperial history of colonial violence and war, at least when it comes to the time period that I study, between roughly 1870 and 1914. More than ten years ago, Robert Gerwarth and Stephan Malinowski postulated a common Western “colonial archive,” “to be understood as common knowledge on the treatment, exploitation, and extermination of ‘sub-humans’ accumulated by the western powers.” They have often been cited but few have since attempted to show how such an archive might actually have come about. In this essay, I hope to present some answers to this question, on the basis of my dissertation, which covered the British, German, and Dutch Empire between c. 1890 and 1914, studied through five case studies (colonial wars in Rhodesia, Sierra Leone, German South West and German East Africa, and Aceh, in the Netherlands East Indies) and the survey of an international corpus of contemporary manuals of colonial warfare.
Generally speaking, the way actors and knowledge of colonial warfare moved across the borders of empires was of a different type than we find in most other studies of transimperial connectivity. When scholars study transimperial science, for instance, they often look at international correspondence networks, conferences, journals, and study commissions. Such avenues of transfer did not really exist for the field of colonial military campaigning. Certainly, there were written publications, particularly articles in military journals, and specialised military manuals. Starting in the 1890s and accelerating until 1914, these indeed often became highly transimperial. To give two examples, Callwell’s famous 1896 textbook on ‘small wars’ covered examples from the British, French, Russian, United States, Spanish, and Dutch Empires; by the third edition of 1906 German, Italian and Portuguese cases had also been added. A Dutch manual of 1913 included the British, French, German and Belgian Empire, and its reference to even relatively minor foreign books and campaigns is striking. The transimperial scope of these texts certainly contributed to standardising and codifying a transimperial body of thought. However, as the reader might have noticed, these publications generally also came rather late in the fin de siècle. In the decades before, another sort of mobility had been (and would also continue to be afterwards) highly important in contributing to the spread of knowledge on colonial war and its violence: the mobility of individuals between empires, who passed on their own, practical experience, frequently in informal conversation. Indeed, when one starts to look for it, one will find many instances of such mobility. This essay will first present four different contexts in which this took place, before spelling out some general implications of these observations.
Non-European transimperial mobility
Any consideration of transimperial connections in colonial warfare should begin with those non-Europeans who constituted the bulk of the rank and file of colonial armies in most territories. While it is generally known that, for the sake of divide-and-rule, colonial army personnel was often recruited from outside of the area where they were to serve, it is less known that soldiers at times also moved between different imperial armies. This was especially the case in the German colonies. For instance, in 1889, when the German ‘explorer’ Hermann Wissmann was tasked to set up a colonial armed force to serve in East Africa, he travelled to Cairo, in British-occupied Egypt, to recruit so-called ‘Sudanese’ soldiers. Many of these ‘Sudanese’ belonged to groups such as the Dinka, Shilluk, Zande or Baggara, who live in the region now known as Sudan and South Sudan. In the 1880s, war broke out in this area when Anglo-Egyptian rule of the region was challenged by a religiously inspired resistance movement under the charismatic ‘Mahdi.’ In these years, many local soldiers came to fight in the Anglo-Egyptian army under British leadership. They received European-style military training and took part in the colonial warfare in the Sudan. After Mahdist forces had driven the Egyptians and the British out of the Sudan for the time being in 1885, a large number of the ‘Sudanese’ soldiers formerly in Anglo-Egyptian service ended up unemployed in the slums of Cairo, where Wissmann was to recruit some 900 of them in 1889.
Interestingly thus, while the so-called Wissmanntruppe that set out for German-claimed territory in East Africa was a new colonial force on paper, the bulk of its African personnel carried extensive knowledge on colonial warfare, due to transimperial mobility. These Sudanese were to form the core of the early colonial troops in German East Africa and some of the highly experienced Sudanese NCOs would serve there right up until the First World War. In 1894, German authorities in the colony of Cameroon would also recruit from the pool of experienced Sudanese soldiers in Cairo in order to constitute a colonial army after their police forces had been disbanded. Apparently, these recruits even included some men who had already fought under Wissmann in East Africa and had later returned to Egypt. The British would also use Sudanese soldiers beyond the Sudan, for instance in the Uganda Rifles who operated in Uganda in the 1890s. Which brings us back to the introductory episode of this essay. Given that the Germans held the ‘Sudanese’ soldiers in such high esteem, it was perhaps little wonder that Robert von Krieg in 1900 had few scruples in incorporating the Uganda deserters into his own German forces.
A second context of high transimperial mobility can often be found in settler colonies. We know that settler societies were frequently highly transnational in their make-up. That this also implied in many cases a transimperial mobility of experiences of colonial warfare is less known. While researching the 1896-1897 Ndebele-Shona War in Rhodesia (current-day Zimbabwe), I regularly noticed individuals in the Rhodesian settler volunteer forces who brought with them previous experiences of colonial warfare from other empires. The most important group among these actors were Boers from the Afrikaner republics, whose familiarity with colonial war was often remarked upon and who even came to form their own volunteer unit, the Afrikander Corps. Another prominent group were Americans, most of whom had originally come to Rhodesia as miners. A good number of these Americans brought experiences of racialised frontier violence from the American West. If we look at transcolonial mobility, we should furthermore mention the considerable number of Australians in Rhodesia at the time, of whom we might surmise that a portion equally had experiences of anti-Indigenous frontier violence.
One particularly striking example of transimperially mobile Americans in Rhodesia was Frederick Burnham, an American who had been involved for a long time in the Apache Wars in the US before moving to South Africa in 1893, becoming one of the foremost scouts of the colonial forces during the Ndebele War of 1896. A number of other Americans are also recorded as having served as scouts in this war, which further hints at their earlier frontier experience. In a way, scoutcraft is indicative of the transimperial itineraries converging in Rhodesia. While Burnham had picked up scouting, according to his own words, “on the American frontier and in fighting Indians,” he added to his skills in South Africa by learning game tracking from some Boers. In 1896, he was then to exchange experiences with Robert Baden-Powell, who served in Rhodesia as a staff officer. Baden-Powell, it seems, in turn also learned from an African scout, the Mfengu Jan Grootboom.
Frederick Burnham’s mobility did not stop there. Already in 1897, he was to be found at another far-away frontier, joining the Klondike gold rush in Canada. Three years later, he returned again to South Africa, this time to serve as Chief of Scouts in the South African War. After 1904, he became involved in American agricultural colonisation schemes in the Mexican borderlands. His preparations there for a war against the resistance actions of the indigenous Yoemen, to whom the land had originally belonged, finally caused his recall from Mexico in 1912.
Burnham is typical of one particular type of individual who, compared to their relatively small numbers, might have had an outsized influence in transimperial knowledge transfer: the hyper-mobile ‘adventurers,’ who moved from frontier to frontier in search of either wealth or war, regularly also crossing imperial borders. We can dismiss such individuals as eccentrics, but they turn up surprisingly often when one looks more closely into frontier wars. Even if their numbers should not be overestimated, they could regularly come to play influential roles, precisely because they could lay claim to previous colonial experience. In this sense the famous anticolonial thinker Aimé Césaire might have been right when he distinguished the ‘adventurer’ as one of the ‘decisive actors’ of European colonialism.
The transimperial beginnings of German colonialism
Transimperial mobility was also of crucial importance in the formation of the German leadership of their early colonial forces. As the German Kaiserreich did not have its own colonies before 1884, it has often been assumed that those Germans who embarked on the early imperial overseas project must have been devoid of colonial experience. This, however, overlooks to what extent transimperial opportunities had allowed a considerable number of Germans to gather experiential knowledge of colonial warfare in the preceding years. This experience-gathering had generally been in the context of the so-called ‘exploration’ of Africa, an endeavour that involved a variety of empires and nations, as an earlier contribution to this blog has already pointed out. Hermann Wissmann and Curt von François, the founders of the colonial armies in German East, and German South West Africa, respectively, had both spent considerable periods of time in the service of the Belgian King Leopold II in ‘exploring’ the Congo Basin in the 1880s. Both had thus been socialised into colonial violence in a non-German context; Leopold’s transnational Congo venture employed Belgians, Britons, Swedes, French, Italians, Austrians, Americans and Dutchmen. Wissmann, furthermore, had been in close contact with Portuguese colonialism and its intermediaries on some of his expeditions. As is clear from his own account of his crossing of Africa from west to east between 1880 and 1883, the main language of communication on that expedition was actually Portuguese.
Such biographies were not limited to the military commanders. Out of the German officers and officials whom Wissmann initially recruited, two had also been to the Congo, while one of the ship captains had long sailed in the Pacific and had seen war there. Around a dozen men were further taken over from the DOAG, the private company that had previously attempted to administer parts of the East African coast on behalf of Germany. The DOAG had included typical ‘adventurers’ such as Friedrich Schröder, who had previously been a tobacco planter on Sumatra in the Dutch Indies, and whose plantation in East Africa became known for extreme brutality vis-à-vis African workers. For all these men, transimperial mobility meant having gained experience with colonial violence long before becoming involved in formal German colonial efforts.
Foreigners in colonial armies
In the nineteenth century, the institution of the military attaché or observer had been increasingly formalised in European-style armies as a channel for mutual observation and learning. For colonial wars, little is known about such observer missions beyond the cases of the British attachés in the German war against the Herero and Nama, and the numerous foreign attachés in the South African War. However, a (far from comprehensive) search for the three empires I considered in my dissertation yielded a surprising number of other such missions. To name several here: the Dutch had at least two different observers in French Algeria in the 1850s and one in 1871, while at the beginning of the twentieth century it was apparently quite easy for colonial officers returning to Europe to disembark in Algeria and be attached to the army there for a short while. A Prussian officer was also attached to the French-Algerian Army both in the 1840s and 1860s, while Prussian Army observers witnessed the British campaign in the Sudan in 1896–1897 and 1898. Furthermore, the British and the Dutch ‘exchanged’ attachés in Southeast Asia, with members of the British Indian Army present in the Aceh War in 1875 and 1877, and a lieutenant from the Dutch East Indies Army accompanying British-Indian operations in Upper Burma 1887, in the aftermath of the Third Anglo-Burmese War.
This suggests that these observer missions should be seen as primary instances in the circulation and transfer of knowledge concerning colonial violence. In reading the reports or accounts of the attachés, however, this is not so evident. These observers were mostly interested in military organisation and logistics; the actual violence was much less remarked upon, or registered as inconspicuous. Given that many of these soldiers already had previous personal experience of colonial warfare, this was maybe unsurprising. Those who did not have this experience generally belonged to the metropolitan armies, and in their case, it is unclear whether their observations found much institutional resonance as colonial war was generally believed to be irrelevant for the sort of ‘conventional’ European wars that these metropolitan armies were preparing for.
Attachés were however not the only foreigners in colonial armies. It is true that, by the fin de siècle, the Europeans serving in institutionalised colonial armies were mostly nationals of the mother country. The British settler colonies (like Rhodesia mentioned above), with their frequent reliance on ad hoc settler militias or volunteers, certainly presented a somewhat exceptional context in this regard. In other places, such as in German South West Africa, there was one standing army, limited to Germans (even if all non-German settlers were also mobilised when war broke out in 1904). In non-settler colonies, the story was similar. But there were also important exceptions. The French Foreign Legion, with its extensive colonial track record, comes to mind, as does the Dutch East Indies Army (KNIL). The Netherlands actively enlisted foreign Europeans into colonial military service via a metropolitan recruitment depot. The percentage of non-Dutch colonial soldiers in the Indies fluctuated considerably but was always substantial, reaching 50.1 % at one instance. Though decreasing from the 1880s onwards, the recruitment of foreigners was only completely abandoned in 1914. The vast majority of these foreigners was always German, Swiss, Belgian or French. The KNIL was highly transnational – but transnational was not always the same as transimperial. My sample of service records suggests that only a fraction of foreign recruits had seen service in another empire. Nevertheless, there was another conduit of transimperial knowledge transfer: the small but steady trickle of former French Foreign Legion soldiers who signed up, and of whom it can be surmised that many had experienced colonial warfare. In a way, these former Legionnaires were ‘adventurers’ as well – men moving from one colonial war to the next, meanwhile crossing the boundaries of empires.
After the description of these contexts of knowledge transfer concerning colonial war and violence, what are some general implications? Firstly, as has been noted more generally for transimperial history, direct colony-to-colony movements were often key. In the field of colonial war, we also have to study different types of networks than we might research in the field of imperial science: here it was particularly the individual mobility of lower-ranking individuals between different empires that was important. And finally, we might also want to look at other places. Looking at the history of colonial warfare, the ‘hubs’ or ‘nodes’ of the imperial ‘web’ are located in decidedly different locales than we see in most other imperial histories. These nodes, where knowledge was drawn together and further diffused, did not lay in the ‘usual suspects’, major colonial cities like Cape Town or Singapore – they rather lay at the ‘margins’, the frontiers and war zones of the different colonies. The kind of places where, in autumn of the year 1900, it was apparently no big deal to simply incorporate thirty mutineers from a British into a German colonial army.
Laurent Dedryvère, Patrick Farges, Indravati Félicité, Elisa Goudin (eds.): Transimpérialités Contemporaines / Moderne Transimperialitäten: Rivalités, Contacts, Émulation / Rivalitäten, Kontakte, Wetteifer, Berlin 2021.
Aidan Forth, Jonas Kreienbaum: A Shared Malady: Concentration Camps in the British, Spanish, American and German Empires, in: Journal of Modern European History 14/2 (2016), pp. 245–267.
Michelle Gordon: Extreme Violence and the ‘British Way’: Colonial Warfare in Perak, Sierra Leone and Sudan, London 2020.
Susanne Kuss: German Colonial Wars and the Context of Military Violence, Cambridge, MA 2017.
Tom Menger: “Press the thumb onto the eye”: Moral Effect, Extreme Violence, and the Transimperial Notions of British, German and Dutch Colonial Warfare, c. 1890–1914, in: Itinerario, published online first 2022.
Bernhard C. Schär: Switzerland, Borneo and the Dutch Indies: Towards a New Imperial History of Europe, c.1770–1850, in: Past & Present, published online 2022.
 Diary entry Robert von Krieg, probably 28 September 1900, reproduced in: G. Huber (ed.): Robert von Krieg: Deutsch-Ostafrika. Briefabschriften von 1900 bis 1906, Ulm/Donau 2001, p. 65.
 Robert Gerwarth, Stephan Malinowski: Hannah Arendt’s Ghosts: Reflections on the Disputable Path from Windhoek to Auschwitz, in: Central European History 42/2 (2009), pp. 279–300, here p. 287.
 C.E. Callwell: Small Wars. Their Principles and Practice, London 1896; third edition 1906.
 M.J.E. Bos: Aanhangsel op het leerboek der tactiek Hoogeboom en Pop: de strijd tegen den Inlandschen Vijand, Breda 1913.
 On German recruitment in other colonies see also: Nicola Camilleri, German and Italian Colonialism Beyond Comparisons: Histories of Transimperial Assistance and Exchange, in: Transimperial History Blog, 20 December 2021, URL: <https://www.transimperialhistory.com/german-and-italian-colonialism-beyond-comparisons>.
 Michelle R. Moyd: Violent Intermediaries: African Soldiers, Conquest, and Everyday Colonialism in German East Africa, Athens, OH 2014, pp. 47–60.
 This was at least reported by Curt von Morgen, who had recruited these soldiers in Cairo: “Meine Lebenserinnerungen,” Bd. 1, Bundesarchiv-Militärarchiv Freiburg, N 227/11, pp. 64–65, 79, 81.
 Gustav Hendrich: The Afrikander Volunteer Corps and the Participation of Afrikaners in Conflicts in Rhodesia, 1893-1897, in: Scientia Militaria: South African Journal of Military Studies 40/1 (2012), pp. 25–48.
 For references to (fellow) Americans in Rhodesia, see for example: Frederick Russell Burnham: Scouting on Two Continents, Garden City, N.Y. 1926. See also the reworked diary of Jim Archer-Burton: Bodleian Library Oxford (BodL), Mss. Afr. S. 2215. For further references: Robert Baden-Powell: The Matabele Campaign, 1896, London 1897, p. 334.
 For a number of references to Australians, see: ‘Correspondents’, Bulawayo Chronicle 19/9/1896, BodL, Mss. Afr. s. 2328/1/3; Newspaper clipping enclosed with letter Willow Plewt(?) to W.L. Jackson 5/7/1896, The National Archives Kew, CO 417/201, f. 451; Baden-Powell: Matabele Campaign, p. 479.
 On Burnham see the recent study by Andrew Offenburger: Frontiers in the Gilded Age: Adventure, Capitalism, and Dispossession from Southern Africa to the U.S.-Mexican Borderlands, 1880–1917, New Haven 2019.
 For example the scout Ingram (mentioned by Burnham, see note 9) as well as Fielder, a scout with the Mashonaland Field Force: E.A.H. Alderson: With the Mounted Infantry and the Mashonaland Field Force, 1896, London 1898, p. 95.
 Burnham: Scouting on Two Continents, pp. 80, 107, 147; Offenburger: Frontiers in the Gilded Age, p. 72.
 Aimé Césaire: Discourse on Colonialism, trans. Joan Pinkham, New York 1972, p. 10.
 Jonas Kreienbaum, The “Exploration” of Central Africa in the Late 19th Century as a Transimperial Project – The Example of Paul Pogge, in: Transimperial History Blog, 23 July 2021, URL: <https://www.transimperialhistory.com/the-exploration-of-central-africa>.
 J.B. Gewald: Learning to Wage and Win Wars in Africa: A Provisional History of German Military Activity in Congo, Tanzania, China and Namibia, in: ASC Working Papers 60 (2005), pp. 1–43; Jan Vandersmissen: De Manuel du Voyageur et du Résident au Congo en de voorbereiding op het dagelijkse leven in de onafhankelijke Congostaat op het einde van de 19de eeuw, in: Quotidiana: Huldealbum Dr. Frank Daelemans 95 (2012), pp. 413–435, here p. 415.
 Hermann von Wissmann: Unter deutscher Flagge quer durch Afrika von West nach Ost: von 1880 bis 1883 ausgeführt von Paul Pogge und Hermann Wissmann, Berlin 1888. See also Kreienbaum: The “Exploration“.
 Max Prager: Zur 10jährigen Erinnerung an die Niederwerfung des Araber-Aufstandes in Ost-Afrika, Stettin 1899, i.a. pp. 6–7.
 Georg Maercker: Unsere Schutztruppe in Ostafrika, Berlin 1893, pp. 18–19.
 Arne Perras: Carl Peters and German Imperialism, 1856–1918: A Political Biography, Oxford 2006, p. 115.
 Ulrike Lindner: Koloniale Begegnungen: Deutschland und Großbritannien als Imperialmächte in Afrika 1880–1914, Frankfurt am Main 2011, pp. 240–248. For the South African war see for instance the series of articles on ‘Reports of neutral military observers during the Anglo-Boer War,’ published in Scientia Militaria: South African Journal of Military Studies between 1973 and 1976.
 Unless indicated otherwise, the part below on colonial military attachés is entirely based on my dissertation research: Tom Menger: The Colonial Way of War: Extreme Violence in Knowledge and Practice of Colonial Warfare in the British, German and Dutch Colonial Empires, c. 1890–1914, PhD thesis, University of Cologne 2021, pp. 227–233.
 On the German observers to Algeria see: Christoph Kamissek: Kriegslust und Fernweh: Deutsche Soldaten zwischen militärischem Internationalismus und imperialer Nation (1770–1870), Frankfurt am Main 2018, pp. 225–232, 299.
 Kamissek however believes the publication by Carl Decker concerning his Algerian observations had a certain influence within the then and future Prussian officer corps: Ibid., p. 232.
 Martin Bossenbroek: Volk voor Indië: de werving van Europese militairen voor de Nederlandse koloniale dienst 1814–1909, Leiden 1992.
 My sample largely covered the years 1875, 1891–1892, and 1895–1897. Koloniaal Werfdepot te Harderwijk, Stamboeken, Nationaal Archief Den Haag (NA), 2.13.09, inv. nr. 1564–1566 / 1636–1639 / 1654–1661. Note that the numbers 1564–1566 do not cover the whole of 1875.
 For a volume with a particularly high incidence of such individuals: Stamboeknummers 6800–7731, NA 2.13.09, inv. nr. 1638.
 For the “imperial web” and its “hubs” and “nodes”, see Tony Ballantyne: Orientalism and Race: Aryanism in the British Empire, Basingstoke 2001.
Beginning August, 2021, Tom Menger is a postdoctoral researcher at the Ludwig-Maximilian University Munich, where he is a member of the Käte Hamburger Kolleg “global dis:connect.” He holds a BA in European Studies and a BA and MA in History from the University of Amsterdam. He recently defended his doctoral thesis at the University of Cologne, titled “The Colonial Way of War: Extreme violence in knowledge and practice of colonial warfare in the British, German and Dutch colonial empires, c. 1890-1914.” His thesis adopts a transimperial approach to the violence of fin-de-siècle colonial warfare, not only outlining the shared discourse and practice of this violence across imperial borders, but also highlighting transimperial connections in this field. A special interest of his concerns transimperial biographies. His recent research interests also include the imperial infrastructure of early colonial oil industries, and how this relates to transimperial and global connectivity.
Tom Menger: The Colonial Way of War: Extreme violence in knowledge and practice of colonial warfare in the British, German and Dutch colonial empires, c. 1890-1914, PhD thesis: University of Cologne 2021.
Tom Menger: “Press the thumb onto the eye”: Moral Effect, Extreme Violence, and the Transimperial Notions of British, German and Dutch Colonial Warfare, c. 1890-1914, in: Itinerario, forthcoming 2022.