Career
He was the leader of a group of 700 Portuguese mercenaries who as musketeers and artillery men fought at the battle of Martaban (1540-1541). They were opposed by Martaban"s defenses which employed another group of Portuguese mercenaries led Paulo de Seixas. Caeiro is said to have seriously considered defecting to the side of Saw Binnya, the ruler of Martaban, who had offered him an enormous bribe.
He rejected the offer after his Portuguese officers threatened to report the matter to the Burmese king.
Caeiro died in 1548, possibly in Pathein (Bassein). He left 13,000 to 14,000 pardaos (Indo-Portuguese silver coins), which were taken into Portuguese India"s treasury, according to a report dated 24 December 1548 by Simão Botelho, the financial superintendent of Portuguese India.