But the old Greek saying that the worst disease of tyranny is the impossibility of reposing trust in its friends was to be justified, and Urquiza, his right-hand man, who had crushed the invaders from Uruguay at the battle of India Muerta and who had overawed all opposition, was at last to prove faithless. He had long been established as Governor of Entre Rios, where he had acted with remorseless cruelty in stamping out disaffection. His first attempts to subvert the authority of Rosas were unsuccessful, but in 1851 he made an alliance with Brazil and one of the Uruguayan factions, and in the December of that year he assembled a force of twenty-four thousand men, crossed the Parana, and marched into Santa Fé. On February 3, 1852, Rosas was overwhelmed at the battle of Casseros near the capital and he fled to Europe. Twenty-five years later he died in Hampshire. Rosas disappeared unregretted. Although it is possible that at the time he came to the front a military dictatorship was the only possible form of government, yet he was one of the worst of the long list of South American tyrants, and it is probably impossible to find any redeeming feature about him except the fact that he encouraged agriculture--a service which was largely neutralised by his hatred of foreigners and foreign commerce. Undoubtedly he stopped the progress of a promising country, not only for the twenty years of his remorseless tyranny but for the long years which were required to recover from the effects of his sanguinary and soulless domination.[51] Anxious as all were for peace and constitutional government, there was some civil warfare and much dissension before the position of Urquiza could be secured. Finally, on May 1, 1853, the Constituent Congress drew up a Federal constitution, and this is practically still in force.[52] Hardly less important was the treaty of the 10th of July following, made with England, France, and the United States, which declared that the Parana and other rivers should be for ever open to navigation.