This introduction addresses the book's main arguments and themes and provides historical background on the history of the Strait of Gibraltar as a political boundary. It also outlines the book's sources and methodology and lays out the chapter-by-chapter narrative arc. The Strait of Gibraltar first became a political border in the sixteenth century, with several smaller borders proliferating on its shores as multiple empires carved out coastal exclaves and spheres of influence. These borders form the crucial starting point for understanding the region's political geography. Borders are the key sites of negotiation between sovereign power and human mobility. They possess material, legal, political, and metaphorical meaning, all of which are central to the ongoing process of mediating relationships among the empires, ethno-religious groups, and trade networks operating in the region.

This chapter examines the process by which the boundary between Spain and the British colony of Gibraltar formed during the second half of the nineteenth century. Although the Spanish conceded Britain's right to maintain a naval garrison there in 1713, they never recognized Gibraltar as a British sovereign space. As a result, no boundary was ever drawn, leaving a vaguely defined neutral zone that worked to the benefit of Spanish political dissidents and smuggling networks. In the nineteenth century, a number of new pressures, including the British ideology of free trade, the politics of revolutionary Spanish liberalism, and the global rise of cholera, created the need for a more precisely defined and regulated border. The result was a somewhat expanded British colony, which bred consternation among later Spanish nationalists but at the time was viewed locally as a practical solution to a range of problems.

This chapter reassesses the origins and consequences of the Hispano-Moroccan War of 1859–1860, conventionally seen as a war driven by domestic Spanish politics. Examining military correspondence pertaining to navigation around Melilla and the Alboran Sea, this chapter argues that the invasion was a defensive response to growing concern that France and Britain were granting legal protection to Moroccan tribes that were hostile to Spain. Because the Spanish prime minister Leopoldo O'Donnell could not declare war against either of those European powers, he launched an invasion against the Moroccan sultan. The goal was not to gain territory but to gain influence in the sultan's court and legal rights to patrol navigation on the eastern Riffian coast. By this measure, the war was more significant and successful than generally believed.

This chapter explores various ways that imperial enclaves could project power over their borders. Examples include the increasing power of European consuls in Tangier to adjudicate conflicts between Jews and Muslims throughout Morocco; the processes by which officials in Gibraltar and Melilla asserted control over regional trade networks by protecting smugglers; and the role of French Oran in serving as a landing point for Spanish and Moroccan refugees and dissidents. Taken together, these examples illustrate the formation of a constellation of power in the trans-Gibraltar borderland that curtailed the ability of the Spanish and Moroccan governments to administer their own laws. The chapter ends with a discussion of the crisis of 1898, which set in motion a cooperative effort by Spain, Britain, and France to clearly delineate imperial spheres of influence, producing the Entente Cordiale of 1904.

This chapter explores the urbanization of the Strait of Gibraltar region, particularly the coastal hubs of Tangier and greater Gibraltar. It draws on the impressions of a growing number of tourists and travelers to depict the rapid changes on both shores of the Strait, which became a magnet for temporary and permanent migrants of diverse social and ethno-religious categories. This cosmopolitan modernism was most on display in leisure settings like the Tangier beach, though it also fueled an underworld of fugitives, bandits, and revolutionaries.

This chapter begins with the emergence of a convoluted new colonial arrangement created by the Act of Algeciras (1906) and the establishment of the Protectorate of Morocco (1912) under France and Spanish administration. This system created several new borders and jurisdictional ambiguities that a number of enterprising individuals learned to exploit. The chapter profiles the rise of three such figures, comparing and contrasting their tactics and accounting for their successes and failures. The Moroccans Bu Hmara and Raisuni, and the Spaniard Juan March, all found ways to amass wealth and political influence by positioning themselves on the borders of rival imperial spheres and inhabiting spaces of diluted sovereign authority. They were skilled at gaining protection from one imperial power while breaking the laws of another. Bu Hmara and Raisuni fell only after multiple powers aligned against them, a fate Juan March avoided altogether.

This chapter looks at the contradictory set of international legal and political requirements prevailing on Spain and Morocco during World War I. There was little will on the part of Spain to enter the conflict, yet it was unclear how to adhere to the requirements of wartime neutrality while also meeting the obligation to administer a portion of the Moroccan Sultanate, a belligerent state by virtue of association with France. German agents, such as the Mannesmann mining firm, exploited this legal and political grey zone to infiltrate the pro-Entente sultanate via the many maritime smuggling networks, brigands, and safe havens of Spanish Morocco. Although this had little bearing on the war's outcome, it convinced the leader of the French colonial army, Hubert Lyautey, that the Spanish officer corps was an unreliable partner.

The Rif War (1921–1926) is typically understood as an anticolonial struggle against Spanish imperialism, but this chapter places the conflict in the broader regional context of the aftermath of World War I. Angered by Spain's pro-German activities during the war, the French Foreign Ministry began a campaign to expel the Spanish from Morocco. Sensing danger, Madrid ordered hasty military action into the Rif Mountains, a provocation that enabled the enterprising nobleman Abd el-Krim to build a Riffian independence army. Abetted by support from contraband networks and benign neglect of French and British patrols, Abd el-Krim built a republic while the Spanish experienced political turmoil culminating in a military coup d'état by Miguel Primo de Rivera. The situation changed only after the French began to see their own positions threatened, at which point Spain and France gradually came together to defeat the Riffian uprising by 1926.

This chapter looks at Spanish administration of northern Morocco after the Rif War. As the physical border between Spain and Morocco disintegrated, Spanish colonial administrators looked for ways to promote "Hispano-Moroccan brotherhood" while preserving religious, social, and sexual boundaries between Moroccan Muslims, Jews, and Spanish settlers. While much scholarship in this area has been dedicated to exposing the Spanish colonial rhetoric of brotherhood to be a ruse, this chapter takes seriously the notion that the Spanish colonial administration attempted to distinguish itself from its French counterpart—even to the point of weakening the positions of the sovereign Spanish cities of Ceuta and Melilla. It aimed to demonstrate greater respect for local customs and traditions and to elevate the zone's Muslim "caliph" to the status of sovereign, although in other ways its practices resembled the French model.

This chapter centers on Gibraltar and Tangier during the tumultuous 1930s. One a British colony and the other an international exclave, both towns were imperial strongholds that depended on Spanish and Moroccan labor. Economic crisis, along with the advent of the Spanish Republic of 1931, stirred working-class politics in both cities, pitting the predominantly working-class Spanish communities against European colonial elites over major municipal issues such as casino gambling and cross-border commerce. The resulting divide continued after the outbreak of the Spanish Civil War in July 1936. Despite official neutrality, European elites in both cities tended to favor groups associated with Francisco Franco's rebellion against the Republic.

This chapter examines the fate of trans-Gibraltar region during Spanish Civil War and the early stages of World War II. Although the insurgent army of Francisco Franco quickly took control of northern Morocco and southern Spain and invited its Nazi and Fascist allies to the strategically crucial region, the Entente order of 1904 proved resilient. New evidence is introduced detailing the Franco movement's success in marshaling anti-French, anti-Semitic, and pro-German sentiments to recruit Muslim support, promising the construction of a new Hispano-Moroccan bulwark in the western Mediterranean. Other new documents indicate how quickly this enthusiasm cooled, however, as it became clear that Nazi agents were preparing to seize a position in northwest Africa without giving consideration for Spanish interests, while the British and much of the Jewish community of Tangier remained supportive of Spanish interests in Morocco.

This chapter analyzes the regional consequences of the advent of American hegemony over the course of two decades. The smuggling and banditry that long characterized the region continued, ultimately undermining the Franco regime's efforts to manipulate its currency and build an autarkic economy. Spanish attention to the southern border did not flag, however, as the Franco regime believed a strong authoritarian government in Morocco was necessary to prevent the spread of communism into northwest Africa and eventually Europe. This consideration, rather than the maintenance of a formal colonial position, guided Spanish action in Morocco from the middle of the World War II and throughout the decolonization era. Despite border conflicts further to the south, authoritarian Spain worked to support a strong independent Moroccan monarchy under Muhammad V and Hassan II, even when a revived Riffian movement presented Spain with the opportunity to restore a neocolonial foothold there.

This chapter discusses the post-World War II reconfiguration of ethno-religious relations that put an end to the modern trans-Gibraltar borderland society as it had developed over the previous century. Jews and Europeans departed Morocco in haste in the 1950s, their safety increasingly uncertain. Spain waged a protracted campaign to recover Gibraltar from Great Britain, closing the border by 1969. Although the effort failed, it put an end to Gibraltar's role as a hub for traffic and circulation around the Strait for over a century. New currents of migration brought Africans northward, making Spain substantially multiconfessional for the first time in its modern history. The chapter concludes with a discussion of the new regional conjuncture and some remarks about the historical changes and continuities over the previous centuries.