Dum Diversas is a papal bull

Papal bull

A Papal bull is a particular type of letters patent or charter issued by a Pope of the Catholic Church. It is named after the bulla that was appended to the end in order to authenticate it....

 issued on June 18, 1452 by Pope Nicholas V

Pope Nicholas V

Pope Nicholas V , born Tommaso Parentucelli, was Pope from March 6, 1447 to his death in 1455.-Biography:He was born at Sarzana, Liguria, where his father was a physician...

, that is credited by some with "ushering in the West African slave trade

African slave trade

Systems of servitude and slavery were common in many parts of Africa, as they were in much of the ancient world. In some African societies, the enslaved people were also indentured servants and fully integrated; in others, they were treated much worse...

." It authorized Afonso V

Afonso V of Portugal

Afonso V KG , called the African , was the twelfth King of Portugal and the Algarves. His sobriquet refers to his conquests in Northern Africa.-Early life:...

 of Portugal

Portugal

Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

 to conquer Saracen

Saracen

Saracen was a term used by the ancient Romans to refer to a people who lived in desert areas in and around the Roman province of Arabia, and who were distinguished from Arabs. In Europe during the Middle Ages the term was expanded to include Arabs, and then all who professed the religion of Islam...

s and pagan

Paganism

Paganism is a blanket term, typically used to refer to non-Abrahamic, indigenous polytheistic religious traditions....

s and consign them to indefinite slavery

Slavery

Slavery is a system under which people are treated as property to be bought and sold, and are forced to work. Slaves can be held against their will from the time of their capture, purchase or birth, and deprived of the right to leave, to refuse to work, or to demand compensation...

. Pope Calixtus III reiterated the bull in 1456 with Etsi cuncti, renewed by Pope Sixtus IV

Pope Sixtus IV

Pope Sixtus IV , born Francesco della Rovere, was Pope from 1471 to 1484. His accomplishments as Pope included the establishment of the Sistine Chapel; the group of artists that he brought together introduced the Early Renaissance into Rome with the first masterpiece of the city's new artistic age,...

 in 1481 and Pope Leo X

Pope Leo X

Pope Leo X , born Giovanni di Lorenzo de' Medici, was the Pope from 1513 to his death in 1521. He was the last non-priest to be elected Pope. He is known for granting indulgences for those who donated to reconstruct St. Peter's Basilica and his challenging of Martin Luther's 95 Theses...

 in 1514 with Precelse denotionis. The concept of the consignment of exclusive spheres of influence to certain nation states was extended to the Americas

Americas

The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 in 1493 by Pope Alexander VI

Pope Alexander VI

Pope Alexander VI , born Roderic Llançol i Borja was Pope from 1492 until his death on 18 August 1503. He is one of the most controversial of the Renaissance popes, and his Italianized surname—Borgia—became a byword for the debased standards of the Papacy of that era, most notoriously the Banquet...

 with Inter caetera

Inter caetera

Inter caetera was a papal bull issued by Pope Alexander VI on , which granted to Spain all lands to the "west and south" of a pole-to-pole line 100 leagues west and south of any of the islands of the Azores or the Cape Verde Islands.It remains unclear to the present whether the pope was issuing a...

.

Issued one year before the Fall of Constantinople

Fall of Constantinople

The Fall of Constantinople was the capture of the capital of the Byzantine Empire, which occurred after a siege by the Ottoman Empire, under the command of Ottoman Sultan Mehmed II, against the defending army commanded by Byzantine Emperor Constantine XI...

 in 1453, the bull may have been intended to begin another crusade against the Ottoman Empire

Ottoman Empire

The Ottoman EmpireIt was usually referred to as the "Ottoman Empire", the "Turkish Empire", the "Ottoman Caliphate" or more commonly "Turkey" by its contemporaries...

. Nicholas V's nephew, Loukas Notaras

Loukas Notaras

Loukas Notaras was the last Megas Doux of the Byzantine Empire. This position had been expanded under the late Palaiologid emperors and functioned as an unofficial Prime Minister, overseeing the Imperial Bureaucracy in place of the Megas Logothetes who had previously...

, was Megas Doux

Megas Doux

The megas doux was one of the highest positions in the hierarchy of the later Byzantine Empire, denoting the commander-in-chief of the Byzantine navy. It is sometimes also given by the half-Latinizations megaduke or megadux...

 of the Byzantine Empire

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

. Some historians view these bulls together as extending the theological legacy of Pope Urban II

Pope Urban II

Pope Urban II , born Otho de Lagery , was Pope from 12 March 1088 until his death on July 29 1099...

's Crusades

Crusades

The Crusades were a series of religious wars, blessed by the Pope and the Catholic Church with the main goal of restoring Christian access to the holy places in and near Jerusalem...

 to justify European colonization and expansionism, accommodating "both the marketplace and the yearnings of the Christian soul." Dum Diversas was essentially "geographically unlimited" in its application, perhaps the most important papal act relating to Portuguese colonization.

Dum Diversas provided:
In 1537 pope Paul III condemned "unjust" enslaving non-Christians in Sublimus Dei

Sublimus Dei

Sublimus Dei is a papal bull promulgated by Pope Paul III on June 2, 1537, which forbids the enslavement of the indigenous peoples of the Americas and all other people...

  but he sanctioned slavery in Rome in 1545, the enslavement of Henry VIII in 1547 and the purchase of Muslim slaves in 1548. In 1686 the Holy Office limited the bull by decreeing that Africans enslaved by unjust wars

Just War

Just war theory is a doctrine of military ethics of Roman philosophical and Catholic origin, studied by moral theologians, ethicists and international policy makers, which holds that a conflict ought to meet philosophical, religious or political criteria.-Origins:The concept of justification for...

 should be freed.

Dum Diversas, along with other bulls such as Romanus Pontifex

Romanus Pontifex

Romanus Pontifex is a papal bull written January 8, 1455 by Pope Nicholas V to King Afonso V of Portugal. As a follow-up to the Dum Diversas, it confirmed to the Crown of Portugal dominion over all lands discovered or conquered during the Age of Discovery. Along with encouraging the seizure of the...

(1455), Ineffabilis et summi (1497), Dudum pro parte (1516), and Aequum reputamus (1534) document the Portuguese ius patronatus

Ius patronatus

Jus patronatus, also spelt ius patronatus, imitating classical Latin orthography, is the term in Roman Catholic canon law for the "right of patronage"....

. Pope Alexander VI

Pope Alexander VI

Pope Alexander VI , born Roderic Llançol i Borja was Pope from 1492 until his death on 18 August 1503. He is one of the most controversial of the Renaissance popes, and his Italianized surname—Borgia—became a byword for the debased standards of the Papacy of that era, most notoriously the Banquet...

, a native of Valencia, issued a series of bulls limiting Portuguese power in favor of that of Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, most notably Dudum siquidem (1493).