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....