Our recent article, War Manifestos, was the first work of legal scholarship to examine the documents that set out the legal reasons sovereigns provided for going to war from the late fifteenth century until the mid-twentieth century. The article described these “war manifestos” and explored their history and evolution over the course of five centuries. We argued that examining these previously ignored manifestos provides new insight into how states exercised the right to wage war. States, we showed, asserted the right to intervene militarily in situations in which a legal right had been violated and all peaceful channels had been explored and exhausted. Many of the “just causes” they gave for war—including to collect debts, to recover tort damages, to protect trading rights, and to enforce treaty obligations—would be inconceivable today. We argued that viewing war manifestos as a set of legal documents not only offers a glimpse into the international legal universe of the past, but it also casts a new light on several ongoing debates, including the intended aim of the US Constitution’s Supremacy Clause and the long-debated Alien Tort Statute passed by the First Congress.
We did not initially study war manifestos with the intent of writing a law review article about them. The article began instead as a modest research project: collecting evidence about the legal causes of war in the early modern period for a chapter in Oona Hathaway and Scott Shapiro’s (then-forthcoming) book, The Internationalists. William Holste, Lisa Wang Lachowicz, and Jacqueline Van De Velde—at the time, 1Ls at Yale Law School—were hired to review “war manifestos” in English, Spanish, French and Latin. As research assistants, Holste, Wang, and Van De Velde set out to find and read a small number of these documents and categorize the legal claims they set out. The project was estimated to take two to three months.
Over weekly progress calls, we noticed that the manifestos possessed similar content, structure, and form—despite publication in different languages, by different monarchs, over different centuries. We had unearthed, in other words, legal documents, communicated by and to an international legal community, reflecting a common understanding of international law or practice. A treasure trove. At the same time, we observed that the reasoning offered in those manifestos appeared to change over time. The formal structure was common, but the legal content varied with the date of publication.
We thus reenvisioned the project as a standalone article that would mine and analyze the details of the manifestos—their origins, the different uses across the centuries and continents, and the range of reasons that sovereigns gave for waging wars. We decided, moreover, to develop the most complete database we could of war manifestos and make those manifestos—and our data—public so that scholars could build on our work. It took us four years to research the history of war manifestos, build the database, write the article, and bring it to print. By the time we completed the article, Holste, Lachowicz, and Van De Velde were not only full co-authors, but they had graduated from law school and begun practicing law.
Even after four years of work, we sometimes felt that we had only scratched the surface of the topic. We, therefore, decided to make the full database and complete text of all the manifestos available online so that others could further plumb the depths of this largely untapped resource for the study of international law.
Research and Challenges
The scope of the project—particularly the sheer number of manifestos, spanning hundreds of years and over a dozen languages—posed uncommon challenges. Below, we discuss our process of defining a manifesto and amassing our collection. We also discuss the coding process and our effort to ensure consistency among independent researchers.
Defining Manifestos. We started with a small collection of what we considered to be “manifestos,” including some that we would later decide to classify not as manifestos but as public relations material—effectively the equivalent of press statements. The team suspected that there were more to be discovered. (Hundreds more, it turned out.) But to discover manifestos, we first had to define them.
In explaining why some of the documents in our initial collection were not manifestos, we began to delineate the boundaries of what was a manifesto. We drew from a comprehensive historical study of manifestos in German, Offizielle Kriegsbegründungen in der Frühen Neuzeit, by Anuschka Tischer. But Tischer is a historian, not a lawyer. For our project, we needed to develop a definition that focused on the legal characteristics of the documents. Manifestos, we came to realize, functioned much like a legal complaint in a lawsuit. And, indeed, this was no accident: we discovered that manifestos arose, in part, out of medieval legal pleadings.
Our definition would evolve to contain five elements. A manifesto was (1) a public document (2) issued by one sovereign (3) against another sovereign (4) that contained reasons (5) for going to war. We then used this definition to classify the documents we had found, to determine whether they met the criteria. Those that satisfied all five conditions were included in the database of manifestos (those that met several, but not all, of the elements were included in the collection as “quasi-manifestos”).
The fourth and fifth prongs were the easiest to apply. Documents that merely described war without setting forth justifications for waging it and those that laid bare grievances without culminating in a call for battle were not manifestos.
The second and third prongs were more difficult. Documents written by non-sovereigns were plentiful; we read many of them. But unlike true manifestos, those documents did not, and could not, end with an effective declaration of war: a key piece, we came to realize, of manifestos as legal complaints. Since non-sovereigns had no legal right to wage war, they could have no “just” basis to attack a sovereign who did. Thus, their calls to war would be unjust—that is to say, illegal.
Conceptually, drawing the distinction between sovereign and non-sovereign authors and recipients meant that our research narrowed to address only “public wars,” or what are today called “international armed conflicts.” The choice to limit our work to sovereigns thus made our dataset useful for studying the reasons given—and accepted—for engaging in international armed conflict over time. It did, however, require that we conduct some historical research to determine whether manifestos were, indeed, issued on behalf of a sovereign. At times, this required fine distinctions. For instance, one of the earliest manifestos in our collection was likely written by the Holy Roman Emperor himself but was published in the name of his loyal subjects. Did that count as a manifesto? Or, to select a more recent example, how were we to treat the manifesto issued by the Confederate States of America, or, for that matter, the American Declaration of Independence? In each case, there were solid arguments on both sides. The only way to resolve these issues was to consider them carefully one-by-one.
The first prong proved the trickiest. To function as a legal declaration, a manifesto had to be written as a public document. War manifestos were intended not only to persuade other sovereigns of the legitimacy of the war but also—and at times even primarily—to persuade their subjects and their opponent’s subjects that the author-sovereign’s cause was just. The manifestos often demonstrate awareness of the public audience. Many contain lengthy introductory paragraphs explaining the author-sovereign’s generous forbearance with the transgressions of the other sovereign until the author-sovereign was forced to stop the unbearable conduct. The undeniable undercurrent of the rhetoric was to highlight the sheer selflessness, patience, and nobility of the author-sovereign! This was also important to the claim of legality—for even though war was legal during the period war manifestos were commonly issued, it was legal only as a last resort. A private letter delivered by courier from one sovereign to another was not a manifesto—because it did not meet the publicity requirement. Publicity could be met in a variety of ways: nailing the document to the church house door, disseminating flyers in the streets, or (later) publishing statements in newspapers.
Finding manifestos. Having analyzed our initial collection, and armed with a clear legal definition of what it meant to be a manifesto, we turned our attention to identifying as many manifestos as possible. Since the manifestos were written across hundreds of years, in various languages, and often as independent booklets or flyers, it proved a massive task to identify and collect them. We are indebted to the librarians at Yale University’s Lillian Goldman Law Library for their heroic work.
We began with Professor Tischer’s work on manifestos. Attached to her publication was an appendix listing roughly 300 documents, spanning the period from 1492 to 1800. We located 273 of these documents; only 163 of these documents satisfied our definition of a manifesto, while 46 fulfilled some, but not all, of our criteria and were therefore designated “quasi-manifestos.”
Our search did not end there. Our research spanned library databases and historical collections, parsed newspaper collections, and worked backwards from known conflicts. The final collection included 573 documents: 264 manifestos, 68 counter-manifestos (manifestos used to justify responding to armed attacks), 53 quasi-manifestos, 129 documents coded but determined not to be manifestos, 27 documents that we identified but could not locate, and 31 duplicates in other languages. Our main body of manifestos stretches from 1492 to 1945, and we ended up pushing our research even further back and further forward.
Coding Manifestos. With the growing collection of manifestos came a predictable problem: managing to actually read them. We had to work through those 573 documents, some spanning hundreds of pages. There were linguistic challenges. We found manifestos in languages ranging from English to Latin to Classical Chinese to Ottoman Turkish. Even when we were able to read those languages ourselves or found research assistants who did, the documents were often written in archaic scripts and styles that occasionally proved difficult to interpret. We could not have managed this project without the help of dedicated and remarkably skilled research assistants—roughly twenty of them by the time we finished the project—who helped us wade through the material.
Although our five-element definition of a manifesto helped to narrow our search, it posed sometimes complex questions to our coding team. In order to classify a document, our coders needed to be sure that the document was in fact public, and that its author and receiver were in fact sovereigns. Answering those questions often required significant historical research and the input of the entire manifestos team. At weekly meetings, it was common for a question about a sovereign, turn of phrase, or skirmish to ignite a fiery debate about how to classify the document.
Even more broadly, making sense of the manifestos and putting them into the proper context often required background research into areas outside our expertise. We researched the rise and evolution of the printed text and various forms of dissemination to understand the different types of manifestos—from freestanding flyers to newspaper accounts; we studied linguistic transitions in early modern Europe; and we examined medieval and early modern political theory to better understand who, exactly, were sovereigns and how they related to one another. We met twice with experts on the rise and fall of the Ottoman Empire to understand how to think about the states that ebbed and flowed in that region. Only a small part of this background research made it into the article, but all of it was essential to understanding the function and content of documents that could, at times, prove opaque.
Beyond War Manifestos: Using, and Improving, the Dataset
As those who know our dataset best, we are quick to note how it can be improved. To begin with, we know that it is incomplete. We were able to identify some manifestos by title (or the sovereign that issued them, or the conflict they were issued to start), but were unable to locate the document itself. Finding those missing manifestos would improve the dataset. Moreover, the manifestos in our collection are heavily Eurocentric—likely due to a variety of factors including our language limitations, the limits of the databases to which we had access, and different practices for preserving and cataloging archival materials outside of Western Europe. (We did make a number of attempts to expand the database; for example, we engaged two outstanding young scholars in classical Chinese, Idriss Fofana and Ling-wei Kung, to help us locate Chinese manifestos.) It would be fascinating to see the extent to which manifesto practice or analogous procedures extended beyond Europe and former European colonies. We hope that others will build on our work, and, indeed, we encourage anyone who locates a document they think may be a manifesto to send it to us so we may include it in the collection.
We hope that this dataset will help breathe new life into modern legal arguments about state practice in times of war. As we show in our article, the dataset shows that some reasons that states sometimes use to justify modern warfare have been around for much longer than we have historically understood. The data shed new light, for instance, on claims of humanitarian intervention, which, contrary to conventional wisdom, were common well before the establishment of modern international law. More generally, the manifestos not only demonstrate that international legal practice has long had form and structure, but also substantiate that claim.
One of our primary goals in preparing this article was to open new fields of academic inquiry. That was the reason behind our decision to create an open-access online database of manifestos. We are certain that there remains a great deal of information in the manifestos in the database that we have yet to discover. We hope that scholars will use these materials to generate new insights into the history of international law, war, and international affairs—and in the process help us better understand our past and our present.
Oona A. Hathaway is a professor of international law at Yale Law School
William S. Holste is an associate at Shearman & Sterling LLP
Scott J. Shapiro is a professor of law and philosophy at Yale Law School
Jacqueline Van De Velde, JD, Yale Law School, 2017, is a law clerk.
Lisa Wang Lachowicz is an associate at Debevoise & Plimpton LLP