Authorities in Asunción, Upper Peru and Montevideo all rejected the authority of the Primera Junta. Having seen little of the benefit of free trade in the preceding years and having suffered heavy taxes from the viceregal capital, they were unwilling to submit to further domination from Buenos Aires. Like most of the interior provinces, they chose to declare their own forms of interim government. Thereafter, following complicated internal civil wars, struggles with Buenos Aires and independence battles with Spain, three new republics emerged from the old viceroyalty: Paraguay (1814); Bolivia (1825); and Uruguay (1828). The frontiers of these republics remained anything but fixed, but they do correspond, in essence, with the countries we know today. The most intractable struggle was the one that involved Uruguay, a region that had seen competing claims by the Spanish and Brazilian authorities during the colonial period, and where fighting involved various alliances between Portuguese, Spanish, local patriots led by the caudillo Artigas , and Buenos Aires and even the British, eager to protect trading interests. Eventually, in 1828, both Brazil and Buenos Aires agreed to the formation of a republic as a buffer nation between the two territories.