As a child Teodósio was brought to the court and made page of king Sebastian I of Portugal. The king was very fond of him and in 1578 insisted on taking him to Africa in his expedition against the king of Morocco. This military campaign was doomed. During the ill fated battle of Alcacer-Quibir, Teodósio remained by his king until the situation become seriously dangerous. Then, Sebastian ordered the servants to take the 10-year-old child to safety behind the lines. The young Bragança was not happy to be set aside and ran away in the first chance. Teodósio caught a horse and went to the front line of the battle, followed by very scared servants. Eventually, like many others, he was wounded in the head and made prisoner. Back in Portugal, his father João of Bragança, went mad with grief and offered a fortune for the ransom of his heir. He also asked king Philip II of Spain to write to the king of Morocco to spare young Teodósio's life. There was no need for such alarm. The king of Morocco left the child go safely and without ransom in August 1579, impressed by the tale of his courage in battle.
Meanwhile in Portugal, the situation was not peaceful. With the disappearance of king Sebastian in the battle, the new king was Cardinal Henry I of Portugal an old childless man. Teodósio was the son of princess Catarina, an ambitious woman that, with her husband the duke of Bragança, aspired to the throne. Philip II of Spain had this aspiration too and used every excuse to keep young Teodósio (great-grandson of king Manuel I and a possible threat) away from the country. Only when he had the crown tightly secured on his hands, did Philip, now I of Portugal, allowed the child's return.
Teodósio became duke in 1583 at his father's death and grew up to be a faithful servant of the Spanish king of Portugal. He defended Lisbon from the attacks of another candidate (António of Crato) and was the responsible the kingdom's security for a long time. Acknowledging this fidelity, Philip II gave the Braganças more lands and titles.
Teodósio's descendants