In 1393, Lisbon was raised to the dignity of a metropolitan archdiocese by Pope Boniface IX with the papal bull In eminentissimae dignitatis.

The bull Inter praecipuas apostolici ministerii, issued by Pope Clement XII in 1737, established that whoever was appointed Patriarch of Lisbon was to be elevated to the rank of cardinal at the next consistory.

The Patriarchs of Lisbon were entitled to unique rights of vesture and ceremony that imitated the grandeur of the papal court: notably, the cassocks of his cathedral canons were scarlet[3] (like those of cardinals), and his chapter has three orders like those of the College of Cardinals.

Among the unique privileges granted to the Patriarch of Lisbon (and never withdrawn, though most have fallen into disuse) were the right to wear the fanon, subcinctorium and falda, vestments otherwise reserved for the Pope.

[4] Also notably, the Patriarch of Lisbon can use a papal tiara (without the cross keys of Saint Peter) over his coat of arms.