Reviewed by: Where Caciques and Mapmakers Met: Border Making in Eighteenth-Century South America by Jeffrey Alan Erbig Jr. Santiago Muñoz-Arbeláez (bio) Where Caciques and Mapmakers Met: Border Making in Eighteenth-Century South America jeffrey alan erbig jr. University of North Carolina Press, 2020 280 pp. The lowland plains of Rio de la Plata in South America, along the territories of modern Uruguay, northern Argentina, and southern Brazil, were borderlands in the eighteenth century: a terrain of shifting distributions of power between Jesuit-Guaraní missions, Portuguese and Spanish cities and ranches, and, importantly, the settlements of a diverse set of Indigenous peoples whose names were recorded as Bohanes, Charrúas, Guenoas, Minuanes, Yaros, and others. Europeans called these last encampments tolderías, from the word toldo (tent). In his book Where Caciques and Mapmakers Met: Border Making in Eighteenth-Century South America, Jeffrey Alan Erbig Jr. argues that while Rio de la Plata in the eighteenth century was an Indigenous area dominated by tolderías, power shifted toward the control of European empires during the century, as the borderlands were replaced by agreed-upon imperial borderlines between the Spanish and the Portuguese. In many ways, this process took place in maps. The book is a deep exploration of the shifts of Indigenous and European power by studying eighteenth-century mapmaking and using current-day mapping technologies (and specifically Geographic Information Systems) as a method. The plains of La Plata were crisscrossed by rivers and small hills, with abundant feral livestock. The missions, Spanish and Portuguese settlements, and tolderías all relied on cattle herding that spread over ample, overlapping territories in seasonal migrations. In the eighteenth century, the founding of the Portuguese city Colônia do Sacramento, together with an increasing Spanish desire for the cattle-derived products like hides or jerky (this last product specifically to feed enslaved plantations in the Caribbean), triggered disputes over imperial sovereignty and led to the development of more concrete lines of demarcation between the two empires. Erbig shows that throughout the century a transition from borderlands to borderlines shifted control away from tolderías to the Spanish and Portuguese. After the 1750 Treaty of Madrid and the 1777 Treaty of San [End Page 605] Idelfonso—which defined a ten-thousand-mile boundary between Brazil and Spanish America—the Portuguese and the Spanish designed joint ventures to establish those boundaries. These expeditions traveled through territories commanded by tolderías. Despite the efforts of the Spanish to "reduce" them to fixed settlements to live under the surveillance of Spanish friars and officials, the tolderías maintained their autonomy and dominated the landscape. It was Native ground, mastered by a series of Indigenous people that the Spanish and Portuguese officers did not know well, could not name accurately, and could describe only through a vague term that alluded to the structure of their mobile homes. European cartographers paid taxes to cross and to lodge on Indigenous ground. Yet the maps they produced emphatically did not include the presence of those who governed the territory. Instead, they created clear-cut lines between the Spanish and the Portuguese. These acts of erasure were the most basic expression of colonialism. In the Spanish and Portuguese colonialist rationale, the mobile tolderías could not be legitimate, sovereign polities. The tolderías were understood as barbarians, relics of an earlier stage of human development, left out of maps, and excluded from the negotiation tables where the interimperial treaties were outlined and the border lines were drawn. The map, heavily involved in colonialism, ratified who was seen as a legitimate sovereign nation. I see this very insight into the silence and violence of the map as one of the book's main contributions. The book explores even further the complex relation between the map and the territory. Even though dismissed from European legal treaties and silenced in the maps, the tolderías maintained the actual control over much of La Plata. The Spanish tried to enforce their sovereignty by removing tolderías from what they believed to be their territory; the Portuguese made pacts with caciques (the leaders of the tolderías) to try to get some real control...