in its western province of La Rioja. Uruguay was too weak militarily to engage in a fight unaided. Since 1862, the Blancos had made repeated overtures to Paraguay, governed by dictator Carlos Antonio López, in an attempt to forge an alliance that might advance both their interests in the Platine region. Upon the death of López, his son, Francisco Solano López, succeeded him as Paraguayan dictator. Unlike the elder López, who strove to avoid encumbering alliances, Solano greeted the Blancos' proposal with enthusiasm. He believed Argentina was working towards the annexation of both Uruguay and Paraguay, with the goal of recreating the Viceroyalty of the Río de la Plata, the former Spanish colony that once encompassed the territories of all three nations. Solano López had, as far back as 1855, expressed this concern, commenting to the Uruguayan Andrés Lamas that "the idea of reconstructing [the old viceroyalty] is in the soul of the Argentines; and as a result, it isn't just Paraguay that needs to stand guard: your country, the Oriental Republic [of Uruguay], needs to get along with my own in order to prepare for any eventualities." In late 1863, Solano López was mobilizing his army and was in talks with Urquiza, the leader of the dissident Argentine Federalists, to convince him to join the proposed Paraguayan–Uruguayan alliance. Brazil and the civil war The developments in Uruguay were closely watched by the Empire of Brazil, which had vital interests in the Río de la Plata Basin. After Rosas fell in 1852, Brazil became the dominant regional power. Its foreign policy included the covert underwriting of opposition parties in Uruguay and Argentina, preventing strong governments that might threaten Brazil's strategic position in the area. Brazilian banking and commercial firms also had ventures in the area, furthering ties within the region. In Uruguay, the bank run by Irineu Evangelista de Sousa (Baron and later Viscount of Mauá) became so heavily involved in commercial enterprises that the economy depended on this source of continued capital flow. About 18 percent (40,000) of the Uruguayan population (220,000) spoke Portuguese and regarded themselves as Brazilian rather than Uruguayan. Many within Flores' ranks were Brazilians, some hailing from the nearby Brazilian province of Rio Grande do Sul. Life along the frontier between Rio Grande do Sul and Uruguay was often chaotic, with hostilities erupting between partisans of various cattle barons, cattle-rustling and random killings. Large landowners