In the beginning of 1825 a group of patriots met in Buenos Aires and planned an invasion of Uruguayan territory. Word was sent to different chiefs in the country districts, and on the night of the 19th of April thirty-three adventurers, with Lavalleja at their head, landed on the shore of the river in the extreme south-western corner of the country. No sooner had they landed than the country rose; the troops sent from Montevideo to meet the band of revolutionists refused to fight, and, deserting the Brazilian banner, joined their compatriots. The revolutionists advanced east along the Negro and the Yi to Durazno, one hundred and thirty miles north of Montevideo, where they found Rivera, then general in the Brazilian service. He promptly deserted and was at once associated with Lavalleja in the command. Lavalleja advanced to the south, calling the population to arms, while the northern detachments rose in response to Rivera. Only fifteen days after the thirty-three had crossed the Uruguay, the flag of the revolution was floating over the Cerrito Hill in front of Montevideo, and Brazilian power was virtually confined to the walls of that city and Colonia. The military chiefs formally declared Uruguay separated from Brazil, and proclaimed its reincorporation with the Argentine. The number of Brazilians then in Uruguay was small, and infantry could not be expected to do much fighting on the plains against gaucho cavalry led by such experienced guerrilla fighters as Rivera and Lavalleja. A division of Rio Grandense cavalry, under their own chiefs, Bento Manoel and Bento Goncalvez, met the Uruguayans at Sarandi. The two armies used substantially the same methods, charging into each other, sword in hand and carbine at shoulder. The Brazilians were caught in a disadvantageous position and suffered a complete and bloody overthrow. The result of this battle was to insure to the revolutionists the continuation of their complete dominance in the country. Their cavalry bands roamed at will up to the very walls of Montevideo. Buenos Aires received the news with extravagant demonstrations of joy, and formal notice was given to Brazil that Uruguay would henceforth be recognised as an integral part of the Argentine Confederation. The emperor promptly responded with a declaration of war. His fleet blockaded Buenos Aires, while he poured re-enforcements into Montevideo and sent an army to invade northern Uruguay. Argentine troops likewise swarmed across the Uruguay River into the country, and the Brazilians could make little progress. On sea they were not more successful, and by the beginning of 1826 Admiral Brown was blockading Colonia and menacing the communications of Montevideo.