Antonio was educated at Coimbra, and was placed in the order of St John.
In addition to papers published to defend his claims Antonio was the author of the Panegyrus Alphonsi Lusitanorum Regis (Coimbra, 1550), and of a cento of the Psalms, Psalmi Confessionales (Paris 1592), which was translated into English under the title of The Royal Penitent by Francis Chamberleyn (London, 1659), and into German as Heilige Betrachtungen (Marburg, 1677).
Having at the age of eighteen become a member of the Society of Jesus, he studied theology at Coimbra, and afterwards became professor in the university of Evora, Portugal.
Circumstances were against him, however, and the count of Castelmelhor, fearing his influence at court, had him exiled first to Oporto and then to Coimbra; but in both these places he continued his work of preaching, and the reform of the Inquisition also occupied his attention.
To silence him his enemies then denounced him to that tribunal, and he was cited to appear before the Holy Office at Coimbra to answer points smacking of heresy in his sermons, conversations and writings.