In “Gender and the Lost Private Side of International Law,” Karen Knop argued that “recuperating private international law as a lost side of international law can open up counter-disciplinary research on gender in the history of international law.”1 In this essay, I use Knop's argument to revisit our understanding of the sixteen century “School of Salamanca”2 and its importance for international legal history from a gender perspective. I focus on the practice of jurists and theologians associated with the School of Salamanca in assessing the validity of marriages of newly converted Indigenous peoples in Brazil (negros da terra), and later the validity of remarriages of Indigenous people and enslaved Africans (negros da Guiné) who had already been married in places from which they had been forcibly removed.3 To do this, these jurists and theologians engaged in private international law (or conflict of laws) reasoning. A key question involved determining what law governed each marriage—was it ius gentium, natural law, or canon law? Examining their arguments, I argue, offers an instance of Knop's insight that recuperating private international law allows us to redress the invisibility of women in the history of international law. In my case study, not only do we better understand “how power operates through international legal concepts and institutions”4 in the private sphere of the family in the colonies, but also, and crucially, how “private international law make[s] visible the effects of colonial . . . law on gender relations and national identity at home,”5 to borrow Knop's words.

This essay takes up Karen Knop's challenge to reconstruct the oft-made distinction between private and public law by engaging private international law (PrIL) as a “lost side of international law.”1 To do so we interrogate the changing fortunes (literally) of women's private property rights in the long nineteenth century—a period characterized by the divestment and reinstatement of gendered rights in national law—focusing on the Nordics, Europe more broadly, and the Colonial world. Following Knop and other feminist legal scholars, and by engaging with questions of what Mariana Valverde calls “scale,”2 we bring women's property rights in conversation with international law. In doing so, we point to sites of engagement where the politico-economic structures of international law are lived, negotiated, reconfigured, and made real.3 We use scale to frame and inform our analysis bringing attention to how the “small” (micro) economics and politics of everyday life, women's labor, and gendered legal concerns, underpin and are an intrinsic part of the “large-scale” structures of international law. “All scales shifts,” Mariana Valverde notes, meaning that such “processes . . . br[ing] certain phenomena into focus that had previously been blurred or pushed to the background.”4 Recovering matters of women's history and everyday life, which, as Knop has argued are often “hiding in plain sight,” with a focus on women's property rights, brings to the fore the critical relationship between family/household, market, and the state, and the fundamental role international law has played in implementing a specific economic vision through the organization of gendered power relations.

In her analysis of James Lorimer's The Institutes of the Law of the Nations (1883), Karen Knop called on public international lawyers to explore the potential of Lorimer's figure of the “private citizens of the world” to illuminate the position of the individual in international law.1 She argued that focusing on the individual's private law dimension revealed hidden understandings and manifestations of the international. This focus, she observed, might even clarify the structural role that nonstate actors and their legal interactions play in shaping sovereign states and their relations.2 This essay builds on Knop's insight to reflect on the role of actors involved in frontier expansion in international law. I examine the settlement of land deemed desert in South America at the turn of the nineteenth century, as private actors used law to incorporate new territories and resources into a capitalist order. Drawing on the work of Argentinian jurist Carlos Calvo, and analyzing specific cases of settlement in the Amazon, I explain how these actors and their legal practices participated in the consolidation of a territorial order of states. Following Knop's prompt, I explore how examining the role of individuals and their private allegiances sharpens our view of how international law exercises power and distributes resources around the world. Combined with efforts to decentralize the history of international law, Knop's private lens shows how individuals seeking to expand the capitalist frontier make international law, not only at the core, but also on the margins and in the interactions between the two.

In this essay, I think with Karen Knop about the heuristic and critical potential of the framework of Foreign Relations Law (FRL) for Private International Law (PrIL). I apply the framework of FRL to the recognition of foreign marriages in Denmark to study how PrIL is operationalized by domestic authorities. FRL helps us see how PrIL's operationalization engages a wide array of legal fields, including Public International Law (PIL), domestic administrative law, and immigration law, as well as the domains of foreign service and foreign policy. In doing so, PrIL in this context draws upon all these fields’ rationales and implicit assumptions. I argue that a FRL perspective not only contributes to PrIL's theoretical self-reflection, but also enhances PrIL's capacity for subversiveness—“its ability to unsettle by showing a given legal system's assumptions and approaches to be a matter of choice rather than simply common sense.”1

In 2021, the French government commissioned two reports on episodes of extreme violence involving France's past: the Algerian War and the Rwandan genocide. Both reports grapple with how “the past haunts the present and the future,”3 a theme that is central to Karen Knop's scholarly legacy. In both reports, legal, historical, and archival expertise are positioned to redraw and recast relations of France to Africa. We argue that the reports’ focus on the role of a particular class of experts (namely archivist and historians, rather than lawyers) reflects France's current approach to narrating historical injustice, emphasizing public memory of violent pasts, rather than legal responsibility of the French state.