By this time also the situation in Uruguay called for the attention of the Junta. The people of the country, despite the pro-Spanish sentiment prevalent in Montevideo, were manifesting signs of revolt against the Spaniards, and when Artigas, the Uruguayan leader, came to Buenos Aires to enlist the aid of the provisional government, the forces of Belgrano that had returned from Paraguay were intrusted to Rondeau to coöperate with Artigas in Uruguay. With the aid of these troops from Buenos Aires, Artigas obtained a signal victory against the Spaniards at Las Piedras, which enabled him to lay siege to Montevideo. With the exception of Belgrano's expedition to Paraguay, which, though unsuccessful in its attempt to bring that province under the control of the Junta, had nevertheless caused no serious military loss, the forces of the Revolution were everywhere successful. Unfortunately, the stinging defeat of Huaquí that the army of Alto Perú met at the hands of Goyeneche in 1811, on the boundary between Bolivia and Peru, threatened for a moment to reëstablish the power of Spain. Had the Argentine forces been successful, Bolivia and Uruguay would never have become separate republics. The complete independence of South America would have been attained ten years before the battle of Ayacucho (1824), and, very likely, with its victorious armies, Buenos Aires would have been able to avoid the terrible civil struggle that, through the lack of a wise and strong central government, lasted till the downfall of Rosas. As it was, the siege of Montevideo had to be abandoned at a time when its garrison was on the point of surrendering; and it was only through the energetic and skillful leadership of Pueyrredón, who was put in command after Huaquí, that of the 23,000 men who composed the original Army of the North, one thousand succeeded in reaching Tucumán. From a purely military point of view, the disaster of Huaquí meant the passing of the initiative from the revolutionary Army to the forces of Spain. In fact, not until 1817, when San Martín crossed the Andes and defeated the Royalists in Chile, were the provinces once more on the offensive. It meant also that the way for a _decisive_ blow at the Spaniards through the north was forever barred; that the attack had to be carried through the west to Chile, first, and then by sea to the heart of Spanish power in Lima; that while troops were being prepared slowly and patiently for this purpose, the constant pressure of the victorious Spanish armies from the north had to be withstood; and last, but by no means least, it emphasized the need for the presence of a strong man to bolster up the provisional government in Buenos Aires itself, which, after the death of Mariano Moreno, was left without a leader of ability and strength commensurate with the magnitude of the task to be accomplished.