He was passionately jealous of foreign interference. Early in his reign he quarrelled with the government of France over questions in regard to the domicile and obligations of foreign residents. The French fleet, assisted later by that of Great Britain, blockaded Buenos Aires. But Rosas defied their combined power; although in this very year (1835) he was menaced by a formidable invasion from the banished unitarians. In Uruguay the "colorados" occupied Montevideo and had formed a close alliance with the Argentine exiles. Montevideo was the centre of resistance to Rosas and from its walls went out expeditions to end the revolts which continually broke forth. In 1842 the allied unitarians and colorados suffered a great defeat from Rosas's right arm in the field, General Urquiza, and thenceforth Oribe, chief of the Uruguayan "blancos" besieged the colorados in Montevideo and controlled the country districts. This apparently ended all hope of expelling Rosas from power. The emigration of the intelligent and high-spirited youth of Buenos Aires to Montevideo and Chile increased. Among these exiles and martyrs to their devotion to constitutional government were many Argentines who shortly rose to the top in politics and whose abilities gave a great impulse to the intellectual movement. Among them were Mitre, Vicente Lopez, Sarmiento, Valera, and Echeverria, who share the honour of establishing civil government in Buenos Aires, and who aided Urquiza in preventing South America from becoming a military empire, and in uniting the Argentine province into a stable nation. [Illustration: BUENOS AIRES IN 1845. [From a steel engraving.]] The longer the tyrant reigned, the less men remembered their own factional divisions. Practically the whole civil population of the capital was ready to support a rebellion. Rosas, however, was to fall, not by a revolution in Buenos Aires, but because his system was inconsistent with the local autonomy of the provinces. He put his partisans into power as military governors, but no bond was strong enough to keep them faithful to his interests. As soon as they were well established in their satrapies, they became jealous of their own prerogatives and of the rights of their people. Rosas ceased to be a real federalist when he made Buenos Aires the centre of his power. He lived there, he raised most of his revenue there, and the city's interests became in a sense synonymous with his own. He excluded foreigners from the provinces, he forbade direct communication between the banks of the Parana and Uruguay and the outside world. Everything was required to be trans-shipped at Buenos Aires so that it might be subject to duty.