Archaeologists just unlocked the secret behind Iraq’s vast ancient ridge and canal systems.

A groundbreaking discovery has shed light on a vast network of earthen ridges and canals in southern Iraq, revealing the scale and significance of an agricultural system constructed largely through slave labor over several centuries. Published research in the journal Antiquity and detailed investigations by an international team of archaeologists provide new insights into the history of the region, particularly the period surrounding the 9th-century Zanj Rebellion. This network, spanning thousands of ridges across the Shaṭṭ al-Arab floodplain near modern-day Basra, was long a mystery but now emerges as a key to understanding the socio-economic landscape shaped by enslaved East African laborers.

A Landscape Shaped by Centuries of Slave Labor

The enormous ridges and canal systems were first documented through satellite and aerial images dating back to the 1960s, revealing over 7,000 manmade earthworks. Radiocarbon and optically stimulated luminescence dating confirmed that these structures were built from the late 9th century through to the mid-13th century AD. This timeline overlaps with the era of the Zanj Rebellion, a major uprising by enslaved East Africans—known collectively as the Zanj—against the Abbasid Caliphate.

The scale of human effort invested in this agricultural network suggests a large and organized system supported by forced labor. “Their history has not been actually written or documented very well in our history,” said Jaafar Jotheri, a professor of archaeology at the University of Al-Qadisiyah in Iraq and a key member of the research team. “So that’s why this (finding) is very important, and what is next actually is to protect at least some of these huge structures for future work. It is minority heritage,” he added.

This discovery underlines the prolonged exploitation of enslaved peoples in the region, highlighting that the use of slave labor for such monumental infrastructure projects likely continued for centuries after the rebellion was suppressed in 883 AD. The work provides crucial context to the social and economic conditions that framed the lives of the Zanj and their descendants, who still live in southern Iraq today.

Drone photograph looking west showing several linear ridge features within the study area. Credit: P.J. Brown et al.

Illuminating a Neglected Chapter of Iraqi History

The archaeological findings expose a significant but understudied aspect of Iraq’s medieval past. While the Zanj Rebellion itself is documented in historical chronicles, much of the everyday life and contributions of the enslaved population have been obscured or overlooked. The immense agricultural system represents both the physical and social legacy of these communities.

This new research emphasizes the importance of preserving such heritage sites, especially in a country where decades of conflict have hampered archaeological work and led to widespread looting. Iraq is often called the “cradle of civilization,” yet this part of its heritage remained hidden for centuries.

Jotheri’s remarks highlight the challenge and opportunity: “It is minority heritage,” he said, underscoring the need for protection and further study. Protecting these earthworks is vital not only for archaeology but also for acknowledging the histories of marginalized groups whose labor shaped the region’s landscape.

Broader Implications for Understanding Forced Labor in History

The findings have far-reaching implications beyond Iraq, contributing to global understandings of slavery, labor, and resistance in historical contexts. The agricultural network reveals how enslaved populations were integrated into the economic fabric through large-scale, labor-intensive projects.

The Zanj Rebellion, while notable for its scale and duration, was part of a longer story in which enslaved people played central roles in sustaining agrarian economies under difficult and oppressive conditions. This discovery underscores the resilience and significance of these communities, whose contributions are now being more fully recognized through archaeology.

By situating the ridges within this wider socio-political framework, the research opens pathways for re-examining other ancient sites worldwide where forced labor might have been involved but remains unacknowledged.