Dum Diversas

18 June 1452, at St Peter's

At St Peter's in Rome, Pope Nicholas V issued the papal bull Dum Diversas to King Afonso V of Portugal. Its closing formula dates it to the fourteenth day before the Kalends of July, which under Roman inclusive counting is 18 June 1452.

The bull granted Afonso and his successors apostolic permission to invade, conquer and subjugate Saracens, pagans and other designated enemies of Christ wherever situated, to appropriate their territories and property, and to reduce their persons to perpetual servitude.

The spiritual accounting

Nicholas offered plenary remission of sins to Afonso and to participating Christians, and extended spiritual benefits to people who contributed money or material support to the campaign.

Participants who died while going to war, fighting or returning were offered restoration to the state of innocence associated with baptism.

The grant also authorised Portuguese kings to appropriate their opponents' movable and immovable property for their own use and profit.

What the bull does not say

Dum Diversas identifies no geography — not Africa, not West Africa, not the Ottoman Empire. Applying it particularly to Portuguese African expansion is a historical interpretation informed by surrounding events and by the later Romanus Pontifex.

The authorisation ran to Afonso V and his Portuguese successors, not generally to every European state, and what it created was a claimed religious-legal license rather than a record of any same-day conquest or slave shipment.

Romanus Pontifex, in 1455, repeated the operative grant and attached it explicitly to Ceuta, Guinea and Portuguese possessions south of Cape Bojador.