Political fragility, environmental stress, and the failure to build lasting cohesion contributed to the fall of Poland’s first kingdom, researchers find.
A new interdisciplinary study published in PNAS examines the dramatic rise and fall of the Piast dynasty—the first medieval kingdom to emerge in what is now Poland. By combining historical records with environmental science and complex systems theory, the researchers offer a new explanation for why this early state rose so rapidly in the 10th century—and why it collapsed just a few generations later.
The study, led by Adam Izdebski of the Max Planck Institute of Geoanthropology and a team of archaeologists, historians, and environmental scientists, brings together an unusually rich combination of sources: high-resolution pollen data, archaeological settlement records, silver coin hoards, and written accounts from Arabic, German, and Polish sources. This comprehensive dataset allows the authors to reconstruct the ecological and political trajectory of the Piast polity in greater detail than ever before.
Their conclusion: the Piast state collapsed not due to natural disaster or foreign conquest alone, but because it failed to build the social networks and institutional cohesion needed to sustain its own rapid expansion. The story of Piast Poland, they argue, is a cautionary tale about the dangers of unchecked extraction and expansion without connectivity or resilience.
Built on Silver and Slaves
The Piast state formed around the year 900 CE in the region of Greater Poland. Its rulers rose to power through wealth accumulated from long-distance trade—especially the Eurasian slave trade, which funnelled silver coins from the Islamic world into Central Europe. Dirhams from Central Asia began appearing in Poland in large quantities by the mid-10th century, often buried in hoards near Piast strongholds. The authors write:
The emergence of this polity was thus closely related to, and no doubt triggered by, the extension of slave trade networks into central Europe. In order to supply them with captives, the Piasts developed the associated technologies of violence, visible archaeologically but also in the textual record. They thus gained access to unprecedented income and were able to rapidly scale up the agricultural production within their core territory with a coerced and displaced labor force. However, the Piast reliance on these bountiful but unstable exchange networks was also a source of considerable vulnerability for their polity.
The influx of silver allowed Piast rulers to build fortified administrative centres such as Poznań, Giecz, Grzybowo, and Ostrów Lednicki. Archaeological evidence from these sites shows major military construction projects occurring at the same time as environmental intensification: forests were cleared, cereal farming expanded, and fire activity increased sharply.
Yet this rapid transformation did not happen organically. The study highlights evidence of population resettlement, likely forced. Communities from newly conquered territories appear to have been moved into the core of the Piast realm to provide labour for construction and agriculture. Place names such as Pomarzany and Czechy hint at foreign origins, and burial styles reflect cultural mixing, or displacement.
An Ecological System Under Stress
Using newly published high-resolution pollen records from Lake Lednica—located just 500 metres from a Piast capital—the researchers show how the environment was dramatically altered during the state’s rise. Deforestation, increased agriculture, livestock grazing, and fire use transformed the landscape in less than a century. But this phase of intensification was followed just as quickly by a collapse.
By the 1040s, the pollen record reveals a marked decline in cereal farming and pastoral activity. Forest species like birch and pine returned, a signal of land abandonment and rewilding. Pastureland fungi also disappeared, indicating that animal grazing had ceased.
At the Kazanie peatland site nearby, the same pattern appears. Agricultural activity declined rapidly after reaching a peak, and the land remained underused for nearly 150 years. The researchers argue this marks the end of state-driven ecological intensification.
A State Without Roots
Despite their military strength and initial success, the Piast rulers never developed the kinds of long-term social structures or administrative institutions needed to sustain their state. Instead, they relied on top-down coercion and external wealth. Even their efforts to use Christianity as an ideological glue—by founding bishoprics and sponsoring missionary activity—proved insufficient. The study notes:
Despite its efforts to quickly create a Christian religious hierarchy, the Piast polity was not able to successfully exploit the cohesive power of religion… nor did it develop a good mechanism of co-opting conquered populations and their elites. Contrary to many successful cases of state building and territorial expansion… the Piast elites had no pre-existing exchange, cultural, religious, or political networks on which to base their emerging, increasingly complex, political organism.
When the kingdom came under pressure in the 1030s—through internal unrest and a devastating invasion by Czech forces under Břetislav I—it could not hold together. The elite power structures collapsed. While some settlements and infrastructure survived, the ruling system itself disintegrated.
Collapse, But Not Ruin
Although the Piast polity vanished from the historical record for several decades, the region of Greater Poland did not descend into total chaos. Archaeological evidence shows that many of the settlements built during the Piast boom persisted. The environmental recovery was uneven, and by the 12th and 13th centuries, human activity had resumed, though at a slower and more sustainable pace.
“The Piast state and its uppermost elite indeed vanished, and this resulted in a sudden end to the Piast ecological intensification,” the authors write. “The written sources suggest that the subjugated population openly rejected both the Piast culture of violence and the associated political-religious ideology… However, Greater Poland as a region and a social–ecological system did not collapse. Rather, the leap forward it experienced during the Piast ecological-economic acceleration was irreversible and provided the basis for further development throughout the medieval times.”
The authors frame the Piast story as a “critical transition” in a social–ecological system. The state rose rapidly due to external capital and violent expansion but never entered a stable phase of conservation or resilience. In the language of complex systems theory, the Piasts built up capital without building the networks necessary to manage it.
A Medieval Warning for Modern Times
Ultimately, the collapse of the Piast state offers more than just a case study in medieval politics. It illustrates the fragile balance between growth and cohesion—between accumulating power and building the networks that allow power to last. The authors argue that this story is particularly relevant today, as modern states grapple with ecological crises, political fragmentation, and runaway expansion.
The study stands out for its interdisciplinary breadth and rich source base, combining science, archaeology, and textual history to tell a powerful story about how early medieval states could rise—and fall—within a few generations.
The article, “Unbalanced social–ecological acceleration led to state formation failure in early medieval Poland,” by Adam Izdebski, Sambor Czerwiński, Marek Jankowiak, Marcin Danielewski, Sabina Fiołna, Raphael Gromiga, Piotr Guzowski, Negar Haghipourj,k, Irka Hajdasj, Piotr Kołaczek, Mariusz Lamentowicz, Katarzyna Marcisz, Jakub Niebieszczański, Paweł Sankiewiczh and Bernd Wagner, appears in PNAS. Click here to read it.
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