At this juncture news came of a great disaster in the north. The Argentines had at first been joined by Bolivian patriots, but the latter were jealous; and the former, bred on the plains, could not well endure the high altitude, suffering in health and efficiency. The Viceroy of Peru rapidly recruited a considerable army among the sturdy and obedient Indians of the high Peruvian plateau. On the 20th of June, 1811, the patriot army was attacked at Huaqui, near the southern end of Lake Titicaca, and was virtually annihilated. Bolivia was lost to the patriots and Spanish authority was re-established as far down as the Argentine plains. This great defeat completely changed the attitude of affairs. The Argentines evacuated Uruguay, and the Spanish colonial authorities everywhere took the offensive. The heroic resistance which the Spanish people were now making to the army of Napoleon's marshals encouraged the Viceroy and governor to believe that Ferdinand would soon again be seated on the throne of his fathers. Spanish ships dominated the delta of the Parana, and the Spanish troops from Montevideo descended at pleasure on the banks of the Plate or its tributaries. The Spanish residents at Buenos Aires plotted against the junta, but their conspiracy was betrayed, and in the middle of 1812 their chiefs, to the number of thirty-eight, mostly wealthy merchants, were arrested and garrotted. The situation of the revolutionary government was so desperate that it is not hard to understand why the junta ruthlessly repressed all signs of disaffection. Victorious Spanish armies threatened them from both Bolivia and Montevideo, and fire in the rear would have been fatal.