[1] Portalegre was established as a see by Pope Julius III, in 1550, taking territory from the archdiocese of Évora and diocese of Guarda.

Its first bishop was Julian d'Alva, a Spaniard, who was transferred to the diocese of Miranda in 1557.

Frei Amador Arraes, the next bishop, was a Carmelite and the author of a celebrated book of Dialogues;[2] he resigned in 1582, and retired to the college of his order in Coimbra, where he remained till his death.

Lopo Soares de Albergaria and Frei Manoel de Gouveia died before receiving the Bulls confirming their nomination.

Among the bishops of Portalegre during the seventeenth century was Ricardo Russell, an Englishman, who took possession of the see on 17 September 1671, and was subsequently transferred to the diocese of Vizeu.