With the arrival of Rondeau, in October of 1812, the siege of the devoted city began on an imposing scale, the army employed for the purpose soon amounting to two thousand men. Destined to drag out its length for almost two years, the first few months of the siege were marked by two events of importance. Vigodet, having received reinforcements from Spain, made a vigorous sally on the last day of the year. At early dawn sixteen hundred men burst out from the gates of the city, surprising and routing the besieging forces as they went, until they won the summit of the Cerrito hill itself, the headquarters of the American forces. With the yellow and red of Spain flaunting from this the Royalists forgot all but their success, and expended their energies in a jubilation that cost them dear. For Rondeau, gathering together his fugitive troops with an amazing rapidity, fell like a thunderbolt upon the cheering crowd, whose joyful clamour turned to groans and death gasps as the stricken mass went reeling back into the city. An event of still greater importance occurred during the first month of the following year. Sarratea himself then journeyed to the camp before Montevideo. But he had company behind that he could not have failed to regard with considerable unease. Notwithstanding his late check, Artigas still remained a power to be reckoned with. Indeed, his vitality had risen to the occasion; he had flung out his summons far and wide, and his power was now infinitely greater than before. Thus, when Sarratea set out for Montevideo, Artigas followed grimly in his wake, having now no mean instrument by means of which to assert his rights--an army of five thousand men. Arriving on the heels of his enemy at the point of hostilities, Artigas was not slow to act. Taking full measure of his advantage, he sent peremptorily to Rondeau, demanding the immediate dismissal of Sarratea from his office of Commander-in-Chief. The order thus given to a subordinate to deal with his superior was quite in accordance with the spirit of the times. As Rondeau, however, did not immediately comply, Artigas took a very simple measure by which to prove that he did not intend to ask in vain. His Gauchos dashed full gallop into Sarratea's camp, and drove off with them all the horses that they found within the establishment. Seeing that a Gaucho army, unhorsed, is as a collection of fish on dry land, the matter was definitely settled by the act. Sarratea retired with the best grace he could muster to Buenos Aires, Rondeau remained in command, and the Oriental and Argentine leaders sat down to continue the investment of Montevideo, one jealous eye of each upon his fellow-chief, the other fixed more casually upon the beleaguered town.