On 15 July 1949, colonel Francisco Javier Arana, Army Chief of Staff, presented president Juan José Arévalo with an ultimatum: if he wanted to finish the term for which he was elected, he had to fire several members of his cabinet and appoint friends of the colonel. Sure of his victory, gave Arévalo until 10:00 pm of 18 July to come up with an answer. On the morning of Monday 18 July, Arana showed up at the Presidential Palace and told Arévalo in a condescending and sarcastic tone that he was on his way to El Morlón, the presidential residence on Lake Amatitlán shore, to confiscate some arms and weapons that had been hidden there after they were confiscated from Dominican exiles in Mexico; the Guatemalan government had given the weapons to those exile to try to take down generalissimo Rafael Leónidas Trujillo in the Dominican Republic. The weapons had been taken out of the Puerto de San José military base and now Arana was on his way to take control of them in the presidential home. Historian Piero Gleijeses has said that this visit was that of an "impulsive man whose patience is gone and that went to the Palace to show off his power and to rush the humiliated president to comply with his ultimatum immediately. But far from scaring Arévalo, he put the president up to speed on his whereabouts, who rushed to set up a plan to exile Arana; dexterously, Arévalo asked him to take colonel Felipe Antonio Girón along -who was the Presidential Chief of Staff- which made Arana believe on his apparent success and that neither Arévalo or Árbenz would stand up to him.