Cartagena had no experience as a seaman. Despite this, he used his influence with Fonseca to secure appointment as Inspector General (
Veedor General) of Magellan's
Armada de Molucca with authority to supervise the expedition's financial and trading operations.
King Charles V of Spain also directed Cartagena to report on the expedition directly, rather than through Magellan as captain-general. This split responsibility would be a source of difficulty during the subsequent voyage. In recognition of Cartagena's influence, and in order to please his supporters, Magellan named him captain of the largest ship of the expedition, the
San Antonio, subject only to Magellan's own authority as captain-general of the fleet. Cartagena earned a salary of 110,000
maravedí, the highest of anyone in the fleet, including Magellan. Tensions surfaced between Cartagena and Magellan as soon as the fleet departed Spain. In councils between captains, Cartagena routinely opposed Magellan's navigation decisions and refused to salute his superior when required by custom to do so. A storm delayed the fleet south of
Tenerife, and food had to be rationed; Cartagena took this opportunity to publicly criticise Magellan and suggest he was not competent to command. Magellan promptly had him arrested, relieved of his command and confined aboard the
Victoria for the remainder of the voyage to South America.
Mutiny Cartagena remained a captive until the fleet reached
Patagonia. On 1 April 1520 he secretly left the
Victoria and reboarded the
San Antonio, where he rallied supporters among the Spanish crew and officers in opposition to the Portuguese Magellan. In company with
Concepcións captain
Gaspar de Quesada, pilot
Juan Sebastián Elcano and thirty Spanish crew members, Cartagena seized control of
San Antonio and declared the vessel independent of Magellan's command. The officers of both
Concepción and
Victoria joined in the mutiny, and on 2 April 1520 a letter was sent to Magellan's flagship, the
Trinidad, demanding that the captain-general acknowledge that the fleet was no longer under his command. Magellan brought the
Trinidad alongside
Victoria and lowered a boat to carry back his reply. When the boat crew reached
Victorias deck, they made a pretense of handing over a letter; when
Victorias captain sought to take it, the boat crew stabbed him to death. Simultaneously, fifteen men from Magellan's ship climbed aboard and attacked the mutineers.
Victorias crew joined their cause and the ship was seized. Cartagena had relocated to
Concepción prior to the battle, and so remained temporarily free. However, only that vessel and
San Antonio remained in the mutineers' hands. Magellan ranged his three ships across the mouth of the bay in which the fleet had anchored, and cleared the decks for engagement with Cartagena's two vessels. In strong winds overnight on 2 April,
San Antonio dragged its anchor and drifted helplessly toward
Trinidad. Magellan ordered a broadside fired, at which the crew of
San Antonio surrendered and allowed the vessel to be retaken. Realising the mutiny had failed, on 3 April Cartagena followed suit and surrendered
Concepción without resistance. ==Death==