The first chief magistrate of independent Uruguay was José Rondeau, an Uruguayan who had become one of the greatest Argentine generals. However, Lavalleja and Rivera were the real factors in the situation, and Rondeau's efforts to conciliate both at the same time failed. The Constituent Assembly, which soon met and framed a paper constitution, was controlled by Lavalleja's partisans. Rondeau was deposed and Lavalleja assumed the reins of power. Rivera prepared to march on Montevideo and dispute the matter by arms, but the representatives of Argentina and Brazil intervened and a compromise was effected. Rivera got the best of the bargain, being given command of the army, and after the constitution had been declared (July 18, 1830), he became, as a matter of course, the first president of Uruguay.
Except for an expedition against the remnants of the once formidable Charrua Indians, the first two years of independence passed in peace. Since the expulsion of Artigas, the country had prospered and its population had risen nearly threefold within twenty-five years, in spite of the bloody fighting which occurred from 1811 to 1817 and from 1825 to 1828. The settlements had spread far back from the coast, and many of the principal interior towns date from this period.
In 1832 the civil wars began again. Lavalleja's partisans organised a conspiracy, and a certain Colonel Garzon took advantage of Rivera's absence from Montevideo to raise a mutiny in the garrison and to issue a pronunciamento deposing the president. The latter soon recovered the city, and after two years of intermittent fighting the Lavalleja party was overthrown for the moment and Rivera finished his term in peace.
Manuel Oribe, a chief of the anti-Rivera faction, succeeded to the presidency by a compromise agreement, but the breach between the two factions had really grown wider and their mutual hatred became irrepressibly bitter. Oribe soon began to persecute his opponents. Meanwhile, the five years had expired during which Uruguayan independence had been guaranteed by the treaty between Argentina and Brazil. Argentina was free to solicit the reincorporation of Uruguay into the Confederation. Rosas, the head of the federalist party, had made himself master of Buenos Aires, and his authority was recognised in most of the Argentine provinces, although the unitarians continued their ineffectual revolts. The new Uruguayan president sympathised with the federalists, while his rival, Rivera, could count on the unitarians. The plan of Rosas was to establish Oribe firmly in Uruguay and through his aid to incorporate that country with Argentina, while the unitarians were desperately anxious that Rivera should triumph, knowing that Montevideo would be a base for the organisation of their own forces for invasions of Buenos Aires and central Argentina.