Sicut Dudum is a papal bull promulgated by Pope Eugene IV in Florence on January 13, 1435, about the enslaving of black natives in Canary Islands by Spanish slave traders. However, the Spanish ignored the Pope and asserted that the black natives were not men but a sort of animal. Eugene IV unequivocally declared the black natives to be rational beings with souls, and denounced any idea to the contrary. He condemned their reduction to slavery in the strongest terms.
SS Eugenius IV
Eugene, Bishop, Servant of the Servants of God,
To our venerable brothers, peace and apostolic benediction, etcetera.
1. Not long ago, we learned from our brother Ferdinand, bishop at Rubicon and representative of the faithful who are residents of the Canary Islands, and from messengers sent by them to the Apostolic See, and from other trustworthy informers, the following facts: in the said islands—some called Lanzarote—and other nearby islands, the inhabitants, imitating the natural law alone, and not having known previously any sect of apostates or heretics, have a short time since been led into the Orthodox Catholic Faith with the aid of God’s mercy. Nevertheless, with the passage of time, it has happened that in some of the said islands, because of a lack of suitable governors and defenders to direct those who live there to a proper observance of the Faith in things spiritual and temporal, and to protect valiantly their property and goods, some Christians (we speak of this with sorrow), with fictitious reasoning and seizing and opportunity, have approached said islands by ship, and with armed forces taken captive and even carried off to lands overseas very many persons of both sexes, taking advantage of their simplicity.
2. Some of these people were already baptized; others were even at times tricked and deceived by the promise of Baptism, having been made a promise of safety that was not kept. They have deprived the natives of the property, or turned it to their own use, and have subjected some of the inhabitants of said islands to perpetual slavery, sold them to other persons, and committed other various illicit and evil deeds against them, because of which very many of those remaining on said islands, and condemning such slavery, have remained involved in their former errors, having drawn back their intention to receive Baptism, thus offending the majesty of God, putting their souls in danger, and causing no little harm to the Christian religion
3. Therefore, We, to whom it pertains, especially in respect to the aforesaid matters, to rebuke each sinner about his sin, and not wishing to pass by dissimulating, and desiring—as is expected from the pastoral office we hold—as far as possible, to provide salutarily, with a holy and fatherly concern, for the sufferings of the inhabitants, beseech the Lord, and exhort, through the sprinkling of the Blood of Jesus Christ shed for their sins, one and all, temporal princes, lords, captains, armed men, barons, soldiers, nobles, communities, and all others of every kind among the Christian faithful of whatever state, grade, or condition, that they themselves desist from the aforementioned deeds, cause those subject to them to desist from them, and restrain them rigorously.
4. And no less do We order and command all and each of the faithful of each sex, within the space of fifteen days of the publication of these letters in the place where they live, that they restore to their earlier liberty all and each person of either sex who were once residents of said Canary Islands, and made captives since the time of their capture, and who have been made subject to slavery. These people are to be totally and perpetually free, and are to be let go without the exaction or reception of money. If this is not done when the fifteen days have passed, they incur the sentence of excommunication by the act itself, from which they cannot be absolved, except at the point of death, even by the Holy See, or by any Spanish bishop, or by the aforementioned Ferdinand, unless they have first given freedom to these captive persons and restored their goods. We will that like sentence of excommunication be incurred by one and all who attempt to capture, sell, or subject to slavery, baptized residents if the Canary Islands, or those who are freely seeking Baptism, from which excommunication cannot be absolved except as was stated above.
5. Those who humbly and efficaciously obey these, our exhortations and commands deserve, in addition to our favor, and that of the Apostolic See, and the blessings which follow there from, but are to be possessors of eternal happiness and to be placed at the right hand of God, etcetera
Given at Florence, January 13th, in the Year of Our Lord, 1435
Appendix B of Fr. Joel S. Panzer's book, "The Popes and Slavery" (Society of St. Paul, 1996) on page 75 from Baronius' Annales Ecclesiastici, ed. O. Raynaldus (Luca, 1752) vol. 28, pp. 226-227. (A special thanks to catholicweb.com for this document)