Born a member of the powerful House of Braganza, he is best known for having served as Viceroy of India and for initiating the Portuguese conquest of Sri Lanka.

He was the son of Dom James, 4th Duke of Braganza from his second marriage to Joana of Mendoça, daughter of Diogo of Mendonça, High-Alcaide of Mourão.

In 1558, he was appointed by the regent Dona Catherine of Habsburg (King Dom John III's widow) as the 20th Governor of Portuguese India, using also the title of 7th Viceroy.

A first expedition, led by Viceroy Dom Constantino de Bragança in 1560, failed to subdue Jaffna, but captured Mannar Island.

According to Mutu Coomara Swamy, Constantino claimed to play a part in capturing and destroying the Tooth-Relic of Gotama Buddha, during the wars of the Portuguese.