Throughout most of the twentieth century, diplomatic history was widely seen as one of the most conservative specializations of the history discipline. A popular caricature had it populated exclusively by older white men, many of whom had a solid background in the diplomatic corps or, alternatively, an unfulfilled dream of serving there. Their main research interest was the foreign relations of European and other Western countries, and the rest of the world came into view only insofar that intra-imperial rivalry and conflict overseas had an impact on international relations in Europe. Throughout most of the twentieth century, diplomatic history, at least in Europe, also seemed more or less insulated from the rest of the history discipline and impermeable to the theoretical and methodological innovations that transformed almost all other branches of the discipline (Watkins, 2008, p. 1).

This began to change during the last decades of the twentieth century, first in the United States and, from around 2000, also in Europe, where historians began to call for a less state-centred and more culturally oriented history of diplomacy (e.g. Lehmkuhl, 2001; Urbach, 2003). Diplomatic historians embraced new methods derived from cultural studies, anthropology, and semiotics and began to shift their focus from inter-state relations to the actors, practices, values, arenas, rituals, translations, and social relations involved in diplomatic exchanges. In doing so, new diplomatic historians aimed to broaden the study of diplomacy from its traditional focus on the formal negotiations and outcomes of diplomacy to focus more on the culture of international relations, including the occluded and intangible aspects of diplomacy. New diplomatic history thus focuses on the diplomatic process and its main actors in order to provide an enhanced understanding of international developments (Scott-Smith and Weisbrode, 2019; cf. Holm and Hellsing, 2015).

In the European historiographic context, new diplomatic historians initially continued to focus on the rich history of intra-European diplomatic relations, particularly the development of new diplomatic practices and international relations on the continent during the formative period from the fifteenth to the early seventeenth centuries (Sowerby, 2016; cf. Mori, 2019). However, some historians also began to explore the cross-cultural dimensions of diplomatic relations between European and non-European powers. The German historian Christian Windler’s Habilitation thesis, La diplomatie comme expérience de l’autre: consuls français au Maghreb (1700–1840), concluded in 1999 and published three years later (Windler 2002), was a pioneering study of what may be called ‘global new diplomatic history’. By consulting a vast number of diplomatic sources in multiple archives, Windler demonstrated how diplomatic actors communicated across cultural barriers and often (but not always) managed to forge a common understanding and a modus vivendi based on shared notions of protocol and mutual respect.

From around 2010 there has been a flood of books focusing on the cultural aspects of diplomatic connections between European and Asian powers during the early modern era. A particular focus of interest has been the relations between European powers and several of the large mainland empires, such as the Ottoman (including Maghreb), Moghul, Persian, and Qing Empires (e.g. Subrahmanyam, 2012; Östlund, 2014; Vink, 2015; Hennings, 2016; Talbot, 2017; Sowerby and Hennings, 2017; Amsler et al., 2019; Biedermann, 2018). A few studies have also dealt with other parts of Asia, such as Japan (e.g. Clulow, 2013) and Southeast Asia (e.g. Bertrand, 2011; Tremml-Werner, 2015; Clulow and Mostert, 2018), as well as West Africa (Brauner, 2015). Most of these studies, many of which are influenced by postcolonial studies, straddle the fields of global and diplomatic history and point to a fruitful line of research that to date has only just begun to be explored (cf. Biederman et al., 2018, pp. 10–11; Mori, 2019, p. 10; Tremml-Werner et al., 2020).

Chronologically, it is striking that all of the studies cited in the preceding paragraph focus on the early modern period. By contrast, the new diplomatic history has to date had little impact on the study of the global nineteenth century, with the notable exception of studies of the global role of the United States (e.g. Hoganson and Sexton, 2021). This chronological bias is probably due to the notion that the contribution of African, Asian, and Latin American actors to the development of international law and diplomatic practices became more or less irrelevant after the turn of the nineteenth century, when European and other imperial powers (particularly the United States) increasingly began to dictate, rather than negotiate, the terms of international relations to non-European states and sovereigns (Alexandrowicz, 1967, p. 2; cf. Koskenniemi, 2001; Anghie, 2005; Pitts, 2018).

However, even if this analysis is broadly correct, diplomacy continued to be an important aspect of imperial expansion and colonial domination throughout the nineteenth and early twentieth century. In order to be seen as legitimate and recognized by the international community, imperial domination had to be sanctioned by international law, which generally meant that a treaty had to be signed between the colonial power and the sovereign who placed him- or herself under colonial rule or domination (Belmessous, 2015). Such treaties may have been unequal, fraudulent, or signed at gunpoint, but their making still required some form of diplomatic negotiation and protocol. Moreover, in order to be sustainable, imperial domination had to rely on a measure of consent, at least by some members of the elites. All of this points to a fruitful corpus of source material that can be studied through the methods and perspectives of new diplomatic history, thereby highlighting, often in great and intimate detail, the encounters between different actors and their cultural practices and value systems. By thus focusing on the process of imperial diplomacy and negotiation, rather than the outcome, new paths of research can be explored in order to contribute to a better understanding of the global nineteenth century.

The study of treaty making and diplomatic relations in the context of nineteenth-century imperial expansion can be characterized as a form a global microhistory, a branch of global history that has attracted much interest in recent years, largely as a reaction against the teleological and macrohistorical bias of some strands of global history (e.g. Ghobrial, 2018, pp. 13–14). Like its ancestor, the Italian microstoria of the 1970s and 1980s, the methods of global microhistory can be likened to those of a scientist using a microscope: by looking at a small segment of a global historical process in great detail, the historian can both challenge and bring nuance and complexity to established and often taken-for-granted grand narratives. Global microhistory is thus not so much a set of themes as a method, or a set of methods, that emphasizes experimentation and hermeneutical understanding through the close reading of historical sources (Trivellato, 2011; Bertrand and Calafat, 2018, p. 10).

There are several advantages of applying the methods and perspectives of new diplomatic history to the study of the diplomatic exchanges that were part of the process of modern imperialism, five of which will be discussed here. First, the shift in focus from the outcome of the diplomatic negotiations (such as the annexation of territory or transfer of sovereignty) to the processes and the actors means that the definition of who is a diplomat can be expanded to include a broad range of state and non-state actors. Examples of such diplomatic actors include colonial officials (regardless of department or line of duty), military officers, businessmen, missionaries, scientists, cultural brokers, and translators. They can also include pirates, explorers, and adventurers, or ‘rogues’, to use Shannon Dawdy’s term (2008, p. 205). Other examples of this broad range of diplomatic actors include male and female members of royal families, aristocrats, religious leaders, local strongmen, warlords, and the like. Turning our attention to such a wide range of actors means applying a functional definition of who is a diplomat, that is, defining a diplomat as any individual who credibly represents a state or polity beyond him- or herself in relation to another state or polity, and engages in negotiations with the general goal of reaching an agreement that all parties can accept (Erlandsson and Naumann, 2019, p. 8).

Focusing on diplomatic actors also means paying attention to the personal motives and interests of those involved. No diplomat, regardless of title of formal position, ever only represented his or her state or sovereign but simultaneously – like any actor – also had personal agendas, values, and priorities, which frequently meant that diplomatic exchanges were influenced by diplomats’ desire for personal gain, status, career, or beliefs (Waquet, 2010). By paying close attention to the actors’ economic, social, and political context, as well as the cross-cultural context in which diplomatic exchanges took place, a more nuanced understanding of international and imperial relations can be generated.

Second, the focus on actors and their motives implies giving equal weight to the perspectives and priorities of European and non-European actors. The challenge of the historian is not only to understand the rationality of the actors in their social and cultural context. It is also to accord at least as much weight and authority to the statements and worldviews of non-Europeans as to those of Europeans, despite the obvious bias in favour of the latter in most nineteenth-century historical sources. By focusing on the contestations over interpretations and priorities associated with diplomatic encounters the historian can challenge the universalizing discourses often found in colonial sources and their modernizing or ‘civilizing’ imperatives. Doing so can serve as an antidote to the tendency of global history to overemphasize circulation, connections, convergences, and entanglements as well as some of its teleological biases (cf. Gänger, 2017; De Lima Grecco and Schuster 2020, p. 439). The task is to account for, on the one hand, disruptions, conflicts, competition, contestations, rivalry, and imbalances, and, on the other hand, negotiation, deliberation, consensus-building, accommodation, and bridge-building, without a priori prioritizing either of these aspects. Difficult as it can be, a way to do so is by trying to understand historical developments from the point of view of the actors involved, taking into account their economic, social, and political context, horizons of expectation, and understandings of the world (cf. Fur, 2017).

Third, new diplomatic history gives attention to the conditions and circumstances in which diplomatic exchanges take place. These include both material aspects and social practices, such as the means and forms of communication, language, translation, ceremony, protocol, and the presentation and exchange of gifts (Holm and Hellsing, 2015, p. 545). It also includes unequal power relations and more or less overt threats of violence, such as the ubiquitous use by colonial powers of so-called gunboat diplomacy. The study of diplomacy as social practice makes it possible to critically examine the origins and functions of diplomatic exchanges, such as negotiations and treaty-making, in themselves. For example, in Southeast Asia the practice of treaty-making was pioneered by the Dutch East India Company in the seventeenth century, leading to the establishment of the practice of regulating international relations by means of a written contract rather than, for example, the swearing of an oath, making a marital alliance, or the paying of tribute (Weststeijn, 2015). Treaty-making, however, was much more than signatures on a piece of paper. The coming into being of a treaty often involved lengthy negotiations, translations, the drafting of different versions of the treaty, the writing of the final wording, often on special high-quality paper or other material, and the signing and sealing of the treaty. Its afterlife, moreover, frequently involved a lengthy (and sometimes abortive) ratification process and the curation and preservation of the treaty document. Treaties were often referred to in later negotiations and could give rise to serious controversies, which sometimes led to violence and even wars. Zooming in on each of these aspects of treaty-making and their different symbolic and practical meanings can reveal novel insights about the nature of diplomatic and imperial relations. An aspect worthy of particular attention is that of translation, which often reveal discrepancies – intentional or not – in the wording and meaning of treaties and other diplomatic documents in different languages (e.g. Fisch, 1979, p. 155; Amirell, 2019, pp. 70–1).

Fourth, the focus on process rather than outcome means analyzing all diplomatic exchanges as part of longer sequences of diplomatic exchanges, often spanning several decades. Each diplomatic negotiation or encounter should thus be understood as part of a series of connected events, in the context of which earlier experiences contributed to shaping subsequent ones. The influence of earlier events is not limited to concrete outcomes, such as treaties or conflicts, but also involves less tangible aspects such as personal relations that could be characterized by, for example, trust, respect, sympathy, friendship, and the ability to communicate across cultural divides – or their opposites. A focus on such emotional aspects of diplomatic relations and exchanges can bring new understandings of how imperial relations were shaped by personal bonds and relations based on feelings and prejudices rather than calculation or rationality (cf. Costigliola, 1997; Merrell, 1999; Plamper, 2015, pp. 34–8).

Fifth, the study of diplomacy from inter-cultural perspectives involves the consultation of a wide range of sources and the careful application of source-critical methods specifically adapted for the task at hand. The traditional sources of diplomatic history, such as diplomatic correspondence, dispatches, notes, records, memoranda, and reports, are still important but they are supplemented with other, largely unofficial, textual sources such as travel accounts, newspaper articles, and personal documents such as diaries, notes, and family correspondence. Depictions of diplomatic exchanges (including ceremonies and other performative aspects of diplomacy), such as sketches, paintings, and photographs, can also be important, as well as the ‘artifacts’ of diplomacy, such as physical treaty documents (with their symbols, seals, signatures, and convolutes), diplomatic gifts, and commemorative objects, such as monuments, inscriptions, and medals (cf. Holm and Hellsing, 2015, pp. 555–6; Biedermann et al., 2018).

The challenge for the historian is to interpret all of these sources critically and to analyze them in their inter-cultural context. A point of departure for doing so is the recognition that diplomatic dispatches, reports, and the like are not accurate reflections of what transpired in meetings and negotiations but are coloured by what the diplomat believed that the reader – such as a minister, a governor, or the general public in a colonial metropolis – wanted to hear and by what might benefit the diplomat’s career or save him or her from embarrassment (Waquet, 2010, pp. 8–9).

The rise of new diplomatic history and its increasingly global orientation in recent years holds great potential for the study of the global nineteenth century. To date, the global historical studies of new diplomatic historians in Europe has focused mainly on the early modern period, whereas North American scholars have long made a greater effort to study the nineteenth century (and later periods), particularly with regard to the global and imperial roles of the United States. These developments have led to the rise of a field of study that deals with diplomacy, not only as cultural history but as inter-cultural history, focusing on the global encounters between diplomatic actors of any cultural, regional, or national origin.

Applying the methods and perspectives of new diplomatic history to the study of the global nineteenth century can shed new light on how imperialism was implemented in different local contexts and contact zones. New diplomatic history can also help to bridge the long-standing gap between two of the grand narratives of nineteenth-century history, that of (intra-) European international history and that of global imperial history (including the global expansion of the United States). Putting these narratives into conversation with one another by means of new diplomatic history has the potential both to reduce the traditional reluctance of diplomatic historians to engage with their subject in a global setting, and to encourage global historians to embrace diplomatic history. Doing so means that the history of international relations and imperial expansion during the nineteenth century can be understood from global rather than colonial or metropolitan perspectives, and inter-culturally rather than Eurocentrically. The goal should be to write a history of the global nineteenth century that fully takes into account the agency, values, and motivations of all the diplomatic actors – European as well as non-European – who contributed to shaping the international and inter-cultural relations that are still part of the world today.

Focusing on diplomatic processes as understood from the point of view of the actors involved can also help to overcome teleological biases in the study of modernization and imperial expansion. Although the general direction of these macroprocesses is well known, they developed in different ways and at different speeds in different parts of the world, not only as a result of the actions and motives of imperial powers but also as a result of the attitudes, values, preferences, and skills of non-European diplomatic actors. Personal relations and emotions also played important roles in inter-cultural diplomatic encounters, and influenced the long-term international relations and the economic, social and political conditions, in the countries or colonies involved, often for many generations, even up until the present.

Finally, a focus on diplomatic processes over long periods of time can serve to question some of the periodizations and watersheds in history that are often taken for granted despite their overtly Eurocentric origins. For example, the notion of the long nineteenth century itself – generally understood as beginning in Paris in 1789 and ending in Sarajevo 125 years later – is based on a prioritization of European historical developments rather than landmark events in other parts of the world, such as, for example, the American Revolution in 1776 or Japan’s victory over Russia in 1905. Studying cross-cultural diplomatic processes and events globally and over long periods of time can challenge such established historical milestones and periodizations and contribute to a truly global history of the nineteenth century.

This article is an early outcome of a collaborative research project entitled Imperial Expansion and Intercultural Diplomacy: Treaty-making in Southeast Asia, c.1750−1920, financed by the Swedish Research Council (2021–2027) and hosted by the Linnaeus University Centre for Concurrences in Colonial and Postcolonial Studies. I wish to thank My Hellsing, Birgit Tremml-Werner and the members of the Research Cluster for Colonial Connections and Comparisons at Linnaeus University for valuable comments and input.