The royalists retreated from Bogotá, and Sámano fled to Cartagena. As for Bolívar, he soon returned to Venezuela, leaving the business of Nueva Granada in the hands of Santander, recommending him to respect the rights of everyone, because, as he said, "Justice is the foundation of the Republic." In Angostura, there had arisen dissensions, and opposition to the vice-president, and even to Bolívar, himself. Some wanted him to be treated as a deserter because he had undertaken the campaign of Nueva Granada without the permission of Congress; some pronounced him defeated; some declared that he was fleeing to safety. Mariño, who had been called to occupy his seat in Congress, seconded by Arismendi, was the center of ill feeling against Bolívar. The vice-president was forced to resign, and Arismendi was elected in his stead. His first action was to appoint Mariño head of the army of the East. The substitution of a military president for a civilian was a vicious precedent which, unfortunately, has been followed in many instances by the Spanish American countries. Arismendi proved, nevertheless, a good vice-president, and retained the cabinet appointed by Bolívar. Affairs were in this condition when news arrived of Bolívar's victory in Boyacá. The Liberator had learned of the disturbances in Angostura on his way to Venezuela. He received also at this time the distressing news of the execution, ordered by Santander, of Barreiro and the other Spanish prisoners taken in Boyacá. Bolívar had proposed to the viceroy an exchange of prisoners, but the viceroy had not even answered Bolívar's communication. The Liberator had never agreed that the cause of freedom should be stained by the blood of prisoners, except in those very exceptional cases, already mentioned, when the War to Death decree was in effect. On some occasions, individual chieftains had not hesitated to commit crimes as heinous as those of the royalists. Though at times Bolívar had to ignore such actions, lest he be left alone by his followers, whenever he could prevent them, he did. He had recommended justice to Santander, who, though otherwise a distinguished officer, an able general and patriot, marred the fame he had acquired by this stupid act of cruelty, an act not to be justified even by the fact that Barreiro had ordered, without any form of law, the execution of many prisoners of war. Once, when a priest was imploring that the lives of prisoners be spared, Barreiro answered: "I am shooting them as I should shoot Bolívar were he ever to fall into my hands." Santander published a proclamation in which he tried to vindicate his conduct, but history has been just in its severity, condemning him unreservedly.