Born at some point during the 18th century, Barboza was subsequently commissioned into the Spanish army, serving in an artillery unit, and was part of the Franco-Spanish force which attempted to capture Gibraltar from Great Britain.

On 27 November 1781, the British Army garrison in Gibraltar launched a sortie from their positions, attacking and destroying several Spanish artillery emplacements before withdrawing.

British commander George Augustus Eliott came across Barboza and offered him assistance, which he refused, asking to be "left alone and perish amid the ruin of my post".

In 1789, American painter John Trumbull included Barboza in his painting The Sortie Made by the Garrison of Gibraltar.

Trumbull later justified his inclusion of Barboza by arguing that he wished to celebrate "noble and generous actions, by whomsoever performed".