Urquiza, greatest of the caudillos, saw that without peace and union Entre Rios could not be insured prosperity. He had no sooner entered Buenos Aires than he took measures looking to the framing and adoption of a federal constitution. After his victory he was named provisional director of the confederation, but he showed no wish to play the role of a Rosas. All the governors met and agreed to the calling of a Constituent Congress, in which each province was to have an equal vote. As a further precaution against the predominance of Buenos Aires the session was to be held in Santa Fe. The provinces were anxious to form a strong federation and the only opposition came from Buenos Aires. Her statesmen did not realise that she was bound to be the centre of the system and that the pull of her superior mass would, before many years, be sufficient to control the aberrations of the satellites. Though the governor of Buenos Aires had agreed on behalf of his province, and though Urquiza's military power was overwhelming, the legislature of that province refused its assent. It was clear that Buenos Aires and the other provinces would not be able to agree upon a basis of union. The ambitious cities of the interior each aspired to take the place of Buenos Aires as the capital, and to this humiliation the latter city would never submit unless after another civil war. Urquiza determined not to use force, and retired to his ranch. As soon as he was out of sight, the city rose in arms against his nominees. The broad-minded Entre Rios chieftain sent back word that he had won the battle of Caseros for the sole purpose of giving Buenos Aires her liberty and that he would not now intervene to prevent her making the use of it she chose. He even disbanded his troops. However, when the Buenos Aireans marched an army to the attack of Santa Fe where the Constituent Congress, attended by delegates from all the other provinces, was holding its sessions, he again took the field. A counter-revolution broke out in the rural districts of the Buenos Aires province against the faction dominant in the city. Urquiza joined his forces to theirs and besieged the town. A land siege was useless without a blockade on the water side, and Urquiza tried to establish one. He was unsuccessful because the commanders of his ships treacherously betrayed him, surrendering to the city party for a heavy bribe. He raised the siege and retired to the northern provinces.