He studied Humanities and Philosophy, having entered the University of Coimbra to pursue a degree in Canon Law, because his uncle King João V had intended him for an ecclesiastical career.

To reach Vienna, with the Seven Years' War underway, he enlisted in the Austrian army, where Manuel, Count of Ourém, his uncle, as well as brother of King John V, had been general.

He was a superior officer of an Infantry Regiment of the Prince of Ligne, his relative, and participated in the war's final campaigns.

[1] In 1778, due to the death of King José I and the removal from government of the Marquis of Pombal, Bragança returned to Portugal, accepting the title of Duke of Lafões.

In 1779, with the abbot Correia da Serra, he founded the Academy of Sciences of Lisbon which began in his residence at Palacio do Grilo.