The Forgotten Cargo: Slavery in the Transpacific Trade

Spanish Galleon. Source: World History Encyclopedia

August 19, 2026 – Pasay City, NCR, Philippines

Article by Nicole Denise Fajilagot

When people talk about the Manila Galleon Trade, they usually think of silk, silver, spices, and porcelain. These goods made Manila one of the busiest ports in the world between 1565 and 1815. But there is a part of this trade that most people do not know about, or simply forget. Along with these valuable goods, the galleons also carried enslaved people. This part of history is often left out of textbooks, yet it played a big role in shaping the lives of many Filipinos, Asians, and other groups during the Spanish colonial period.

Manila as a Center of the Slave Trade

Manila was not only a hub for trading goods. It was also a place where people were bought and sold. According to Mangubat (2024), the whole city functioned like a slave market, with auctions happening right in the public squares within the city walls. Buyers and sellers made deals openly, and there was no single system keeping track of how many people were sold. This is why historians still find it hard to know the exact number of people who were enslaved through this trade. The people sold in Manila’s slave markets were divided into two brand groups: “negros,” referring to Black captives, and “chinos,” a term used loosely for people from many parts of Asia (Mangubat, 2024). These captives came from different places, such as the Muslim sultanates in the south, the Malabar coast in India, Mozambique, the Malukus, and Malacca. Many were taken through raids, wars, or slave trading networks run by Portuguese traders, who supplied a large number of the enslaved people brought into Manila (Seijas, 2008).

Life as Cargo

Being classified as cargo meant enslaved people were treated the same way as goods, not as human beings. Mangubat (2024) shares an account of how ships heading to Acapulco were often overloaded, forcing enslaved people to be squeezed into cramped spaces below deck. The journey across the Pacific Ocean took about six months, and conditions were harsh. Passengers would sometimes wake up to find several people had died overnight from hunger, disease, or the difficult conditions of the trip. Women who were enslaved suffered even more.  Many were sexually abused during the voyage, a problem so widespread that King Philip III of Spain ordered a ban on shipping female slaves in 1608. Sadly, this order was mostly ignored, and the abuse continued for many more years.

Historian Tatiana Seijas (2014) describes this same journey in her research on enslaved Asians in colonial Mexico. She explains that people captured from many different places, such as India, Indonesia, and the Philippines, were forced together and grouped under one label, “chino,” once they reached the ships. This mixing erased their different backgrounds and identities, turning them into a single category of property before they even set foot in Mexico. Seijas (2014) also notes that many of these captives never chose to make the voyage. They were bought, kidnapped, or handed over through deals made by traders, then loaded onto galleons bound for a country they had never seen.

Chino Slave Origins. Source: Asian Slaves in Colonial Mexico: From Chinos to Indians

The Business Behind the Trade

Even though the Spanish crown spoke against the mistreatment of enslaved people, it still benefited from the trade. Aside from regular taxes on goods, the government also issued licenses that allowed merchants to legally trade enslaved people. This shows how slavery, while criticized on paper, was still allowed to continue because it brought money into the colonial economy. Local elites also played a part in keeping the system alive. Even before the Spanish arrived, slavery already existed in the Philippines, where it was tied to debt or captivity after war. Spanish colonizers used this existing system to justify continuing the practice, relying on native leaders and their slaves to help run the colony (Mangubat, 2024). However, scholars point out that slavery in the pre-colonial Philippines worked differently. According to historian William Henry Scott (1994), the pre-colonial alipin system was closer to debt bondage than to slavery as property. People became alipin mainly through debt, capture in local raids, or birth, but many still lived with their own households, owned some belongings, and could work their way toward freedom over time.

Laws, Contradictions, and Decline

Spanish law had a complicated relationship with slavery. As early as 1542, laws were passed to protect native people in Spanish colonies from being enslaved and by 1574, a specific decree banned the enslavement of native Filipinos. Despite this, loopholes remained. If someone was captured during a “just war,” especially against Muslim groups in Mindanao they could still be legally enslaved. This gave colonizers a legal excuse to continue capturing and selling people from certain groups. Court cases from this period show how enslaved individuals sometimes fought for their freedom. One example is the case of Bartolome Manuel, whose legal status was questioned in a Spanish court in 1655. His case, along with several  others, reveals how enslaved people used the legal system itself to try to gain their freedom, even if the outcome is  not always in their favor (Mangubat, 2024). By the seventeenth century, the Transpacific Slave Trade slowly declined. Some historians believe this happened because the Atlantic slave trade grew stronger and pushed out competition from other slave markets, including one in Manila. Still, this did not mean slavery disappeared completely. It simply changed form, shifting into other systems like forced labor and debt bondage that continued to affect many Filipinos long after the galleon trade ended.

Traces Left Behind

Even centuries later, science has found proof that this trade really happened. A genetic study of people living in Guerrero, Mexico, especially in the port city of Acapulco, found that many residents carry Southeast Asian ancestry that races back to around the 1620s, matching the peak years of Manila Galleon Trade (Rodríguez-Rodríguez et al., 2022). These researchers found that this Asian ancestry mostly came from the Philippines and parts of Indonesia, which lines up with historical records of enslaved “chinos” being brought to Acapulco. This shows that the impact of this forgotten trade did not just disappear. It is still written into the bloodlines of people living in Mexico today.

Conclusion

The story of the Manila Galleon Trade is usually told through the goods it carried, but it is also a story about the people who were forced into its cargo holds. Understanding this hidden side of the trade helps give a fuller picture of Philippine maritime history, one that includes both economic achievement and human suffering. By learning about the experiences of enslaved Filipinos and other Asians during this period, we gain a better understanding of how deeply the Philippines was connected to the wider world, not just through trade but through shared histories of struggle and survival. Remembering this part of history is important, not to dwell on pain alone, but to honor those whose stories were left out for far too long.

References

Mangubat, L. (2024). Silk, Silver, Spices, Slaves: Lost Tales from the Philippine Colonial Period, 1565–1946. Faction Press.

Rodríguez-Rodríguez, J. E., Ioannidis, A. G., Medina-Muñoz, S. G., Barberena-Jonas, C.,

Blanco-Portillo, J., Quinto-Cortés, C. D., & Moreno-Estrada, A. (2022). The genetic legacy of the Manila galleon trade in Mexico. Philosophical Transactions of the Royal Society B, 377(1852), Article 20200419. https://doi.org/10.1098/rstb.2020.0419

Scott, W. H. (1994). Barangay: Sixteenth-century Philippine Culture and Society. Ateneo de Manila University Press.

Seijas, T. (2008). The Portuguese slave trade to Spanish Manila: 1580–1640. Itinerario, 32(1), 19–38. https://doi.org/10.1017/S0165115300000209

Seijas, T. (2014). Asian Slaves in Colonial Mexico: From Chinos to Indians. Cambridge University Press.