Fortunately for the independence of the provinces of the Plata, there arose, at this critical juncture, men like Belgrano, who by his victories of Tucumán and Salta, stemmed the flood of Spanish invasion after Huaquí; San Martín, who by his conquest of Chile and Lima, was to force the Spaniards into the fastnesses of the mountains of Peru, where his veteran troops, delivered by one of the greatest acts of self-denial in the record of history into the hands of Bolívar, sounded the knell of Spanish dominion on the battlefields of Junín and Ayacucho; Güemes, who after the battle of Sipe-Sipe, a disaster comparable only to Huaquí, was able, with the aid of his intrepid _gauchos_, to protect the communications of the army that was being prepared by San Martín in Mendoza; Rivadavia and Pueyrredón, without the stimulus of whose leadership the provisional government would have succumbed under the weight of the responsibilities it had assumed. [Illustration: BELGRANO EN TUCUMÁN _Navarro y Lamarca, Historia general de América_ _Fortuny_] Immediately after the victory of Tucumán, obtained by Belgrano against the Spanish forces that invaded northern Argentina after the defeat of Huaquí, the siege of Montevideo was begun once more, both as a result of that victory and of negotiations with Brazil, whereby the troops of that empire, which had come to the aid of the Spaniards, were to withdraw from Uruguay. The patriots were soon able, in spite of the friction that arose between Artigas and the Argentine troops, to pin the Spanish forces within the inner circle of the defenses of Montevideo. It was in connection with this campaign against Montevideo that San Martín in 1813 won his first victory against the Spaniards, at San Lorenzo, on the shores of the Paraná. By this victory an end was put to the foraging expeditions that the beleaguered garrison of Montevideo sent to the province of Entre Ríos. Thus the only immediate avenue for the supplying of provisions was closed. The desertion, however, of Artigas, and the harassing by his Uruguayan bands of the besieging forces, threatened once more to bring about the abandonment of the siege. The defeat of the naval forces of Spain in the Plata River by Admiral Brown, an Irish sailor in the service of the government of Buenos Aires, came at this time most opportunely to close _all_ avenues of replenishing, and the garrison was forced to capitulate. The taking of Montevideo was an event of the utmost importance for the Revolution, since it made possible the concentrating of all forces for an attack upon Peru, the heart of Spanish power in South America.