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Upper Paraguay; Borders; Treaty of Madrid
This dissertation investigates the formation of the Upper Paraguay border in the 18th century, arguing that this space was a dynamic zone, not a static line defined by treaties. The work explores how the colonial imaginary, driven by myths such as the "Laguna de los Xarayes" and "Isla Brasil," clashed with the reality of occupation. The research analyzes the pragmatic actions of expeditions of monsoons and backwoodsmen, who sought to convert cartographic claims into de facto possession, and the subsequent legal consolidation through the creation of villages and the diplomacy of the Treaty of Madrid. The analysis is based on primary sources from institutions such as the Overseas Historical Archive, the Portal de Archivos Españoles, and archives in Mato Grosso, São Paulo, and Buenos Aires. The work concludes that the Upper Paraguay border was the product of a multifaceted process that intertwined myths, military strategy, and a complex political, legal, and cultural framework.