Nevertheless, in this very year the growing settlement all but came to a bloody and untimely end. A rising of the Charrúa Indians in the immediate neighbourhood of Montevideo resisted all the efforts made to subdue it. Over one hundred Spaniards were slain and the royal forces put to rout. The natives, drunk with success, were on the eve of entering Montevideo and of slaughtering the inhabitants, when a Jesuit missionary, Padre Herán, intervened, and prevailed on the Indians to desist from their purpose.
Scarcely had this danger passed when another, and remoter, came into being to take its place. The restless Portuguese having given peace to the Banda Oriental for ten years, doubtless considered the period unduly prolonged, and thus invaded the Rio Grande on the northern frontier. Lavala's successor, Don Miguel de Salcedo, a ruler as impotent as the first had been strong, contented himself with besieging Colonia as a counter-stroke, while the Portuguese forces were left free to complete the conquest of Rio Grande. This they continued to hold, despite the terms of an armistice arranged in 1737 between Spain and Portugal.
For ten years after this no historical event of importance occurred to disturb the progress of Uruguay. In 1747 a rising of the Indians was utterly crushed at Queguay, and two years later Montevideo, now acknowledged as a town of importance, was accorded a Governor of its own. Don José Joaquin de Viana was the first appointed to the post. His opinion of its urgency is evident from the fact that he only took office in 1751.
By the treaty of 1750 King Ferdinand VI. of Spain ceded to Portugal the northern stretches comprising the Jesuit Missions of Uruguay and the present province of Rio Grande in exchange for Colonia. As a stroke of commercial diplomacy the bargain was undoubtedly a failure, since by its means Spain not only lost for ever two flourishing provinces, but, in addition, the Jesuits and their Indians were obliged to forsake the field of their labours, and to migrate in search of fresh country.
This, however, was not the case with all alike. A large number of the Indians, deeply attached to the neighbourhoods wherein lay their homes, refused to follow the missionaries, and in the end resisted the unwelcome decree. Pitted against the combined forces of Buenos Aires, Uruguay, and Brazil, their cause had not a momentary chance of success. After suffering various defeats, they were finally routed and almost exterminated at Caaibate in 1756, when the native loss amounted to 154 prisoners and 1,200 dead, at the very moderate Spanish cost of 4 dead and 41 wounded. The character of the action is sufficiently evident from the butcher's bill. A certain number of the surviving Indians were taken to Maldonado, and, settling there, formed the nucleus of the present town.