In May 2026, Pope Leo XIV delivered one of the most consequential moral reckonings in modern Catholic history: a formal acknowledgement of the Vatican’s historical failures regarding slavery and the transatlantic slave trade. The apology marked a significant moment not only for the Roman Catholic Church but also for the broader global conversation about historical accountability, colonialism, and human dignity. For centuries, historians, theologians, and activists have debated the role of the papacy in legitimising systems of conquest and enslavement during Europe’s age of expansion. Pope Leo XIV’s statement directly confronted that legacy.
Slavery was deeply embedded in the ancient and medieval world long before the rise of European colonial empires. Early Christian societies inherited systems of slavery from the Roman Empire, and although Christian teaching emphasised the spiritual equality of all souls before God, the Church did not abolish slavery as an institution.
Throughout the Middle Ag es, forms of servitude, forced labour, and slavery continued across Europe, North Africa, and the Middle East. Church authorities often distinguished between what they considered “just” enslavement — such as prisoners captured in war — and unjust enslavement. This distinction would later shape the Vatican’s approach during the colonial era. The controversy surrounding the Church’s role in slavery centres largely on a series of papal decrees issued during the 15th century, when Portugal and Spain began expanding into Africa and the Americas. Among the most debated documents was Dum Diversas (1452), issued by Pope Nicholas V. The decree authorised the Portuguese crown to conquer non-Christian territories and reduce certain populations to “perpetual servitude.” Historians widely regard this language as one of the earliest religious justifications for European imperial slavery.
A second decree, Romanus Pontifex (1455), expanded Portuguese authority over trade routes and territories along the African coast. The document granted religious approval to imperial expansion and indirectly helped legitimise the emerging Atlantic slave trade. These decrees later became associated with what scholars call the “Doctrine of Discovery” — the belief that Christian European kingdoms had a divine right to claim lands inhabited by non-Christians.
The Vatican’s history on slavery was never entirely uniform. Some Church leaders opposed particular forms of enslavement, especially the abuse of Indigenous peoples in the Americas. In 1537, Pope Paul III issued Sublimis Deus, declaring that Indigenous peoples were fully human and should not be enslaved. The document rejected arguments that native populations lacked souls or rationality. Yet the declaration had major limitations. Enforcement was weak, colonial powers often ignored it, and the broader institution of slavery — especially the enslavement of Africans — continued for centuries.
As European colonial empires expanded, Catholic kingdoms, including Portugal, Spain, and France, continued participating in slave systems. Religious institutions, monasteries, and some missionary networks also benefited economically from forced labour in colonial territories.
One of the central criticisms historians make is that the Catholic Church condemned slavery as a universal moral evil relatively late compared to abolitionist movements elsewhere.
A stronger institutional rejection emerged only in the 19th century. In 1888, Pope Leo XIII issued In Plurimis, condemning slavery and praising abolition efforts. By then, however, slavery had already been abolished in much of the Western world, including: the British Empire in 1833; the US in 1865; and several Latin American nations during the late 19th century. Critics argue that while individual Catholics participated in abolitionist movements, the Vatican itself was slow to confront slavery directly and unequivocally.
Previous popes, including Pope John Paul II and Pope Francis, expressed sorrow for the actions of Christians involved in colonialism and slavery. However, Pope Leo XIV’s statement went further by explicitly acknowledging institutional responsibility within the Church hierarchy itself. For many historians and theologians, the significance of the apology lies in its willingness to address not merely individual wrongdoing, but structural and institutional failures extending across centuries.
Pope Leo XIV’s apology represents a profound symbolic shift for one of the world’s oldest institutions. By confronting the contradictions between Christian teachings on human dignity and the Church’s historical entanglement with slavery, the Vatican has opened a new chapter in its relationship with history.
For supporters, the apology is an overdue act of moral honesty. For critics, it is only a beginning. But few dispute that the statement marks one of the most significant acknowledgements ever made by a Pope regarding the Catholic Church’s role in the history of slavery.
The writer is a France-based haematologist.