A multidisciplinary study of a 3rd-century mass grave unearthed in Croatia has revealed that the Roman soldiers buried there were not locals, but rather a genetically diverse group from distant corners of the empire. The analysis of ancient DNA (aDNA), combined with archaeological and bioarchaeological evidence, provides a stark picture of the multicultural nature of the Roman army during the tumultuous “Crisis of the Third Century” and points to a violent end in a pivotal battle.
The findings challenge previous assumptions about legionary recruitment and offer a rare, detailed snapshot of the individuals who fought and died on Rome’s frontiers. Discovered in 2011 at the site of the former Roman city of Mursa, now Osijek, Croatia, the grave contained the remains of seven adult males who were unceremoniously thrown into a well, a burial practice far outside of Roman customs and indicative of a mass casualty event. Radiocarbon dating places the interment around 260 CE, a period of intense civil war and military coups throughout the empire.
A Grim Discovery Outside City Walls
Archaeologists made the discovery during excavations in Osijek, uncovering a well filled with seven completely preserved human skeletons. Unlike typical Roman burials, which were often orderly and accompanied by grave goods, this site showed signs of haste and emergency. The haphazard arrangement of the skeletons suggests the bodies were thrown into the well quickly, likely in the aftermath of a major conflict. Such mass burials were highly unusual in the Roman Empire and were typically reserved for extreme circumstances like plagues or catastrophic military defeats. The location of the grave outside the city walls further supports the theory that these were casualties of a battle whose remains required swift disposal.
Evidence of a Violent End
Bioarchaeological analysis of the remains determined that all seven individuals were adult males, estimated to be between 36 and 50 years old. They were described as taller and more robust than the average for the period, with skeletal markers suggesting lives of strenuous physical activity. This evidence, combined with numerous pathologies, strongly points to their identity as soldiers.
The Battle of Mursa
Historical records and the direct radiocarbon dates align the deaths with the Battle of Mursa in 260 CE. This conflict was a key event during the Crisis of the Third Century, a 50-year period when the Roman Empire nearly collapsed under the combined pressures of invasion, civil war, and economic instability. The battle was fought between the forces of the ruling Emperor Gallienus and the usurper Ingenuus. Historical sources note that Gallienus showed no mercy to the defeated supporters of Ingenuus, and mass executions may have followed the battle. The context suggests these seven men were casualties of this brutal engagement, their bodies discarded in the nearest available pit.
Wounds of a Soldier’s Life
The skeletons bore the scars of military life and a violent death. Forensic analysis identified a range of injuries, both healed and unhealed. These included blunt force trauma and enthesopathies, which are changes to bone where tendons and ligaments attach, commonly associated with rigorous activity. At least two of the individuals had puncture wounds on their torsos, consistent with injuries from arrows or spears. Some skeletons also showed signs of pulmonary disease, suggesting the men may have been in poor health before their final battle.
Genomes Reveal a Diverse Legion
The most groundbreaking aspect of the research came from ancient DNA analysis, which was successfully performed on four of the individuals. The genomic data confirmed that the Roman army was a melting pot of different peoples, drawing its manpower from across the vast empire. This multidisciplinary study provides concrete biological evidence for the mobile and diverse nature of the individuals who comprised the military machine.
A Mosaic of Ancestries
The aDNA sequencing showed a high degree of genetic diversity among the soldiers. Analysis of their paternal lineages revealed that they belonged to distinct haplogroups, further underscoring their varied geographic origins. Their genetic profiles plotted closer to modern northern and eastern European populations, while one soldier’s DNA showed a closer affinity to modern-day Sicilians. This heterogeneity confirms that the soldiers were not a homogenous local fighting force but a collection of individuals from different parts of the Roman world, brought together by military service.
Not from the Local Population
Crucially, the study found that none of the soldiers shared a genetic continuity with the preceding local Iron Age population of the Mursa region. This finding is significant because other Roman-era individuals excavated in Mursa in different contexts did show genetic links to the local populace. The clear genetic distinction of the men in the mass grave strongly supports the conclusion that they were outside soldiers stationed in or passing through Pannonia as part of a mobile military unit, a common practice for the Roman army to prevent legions from forming local allegiances.
Life on the Roman Frontier
Beyond cause of death and ancestry, scientific analyses provided insights into the daily lives of these soldiers. Stable isotope analysis of carbon and nitrogen in the bones shed light on their diet, a key component of understanding their lifestyle and geographic origins before arriving in Mursa.
A Soldier’s Standard Diet
The isotopic data indicated that the men consumed a mixed diet based on C3 and C4 plants, which could include wheat, barley, and millet. Their protein intake was limited, consisting of some terrestrial animal sources, with negligible consumption of marine fish. This dietary profile is highly consistent with historical accounts and previous isotopic studies of the Roman military diet in inland provinces like Pannonia. It reflects a logistical system designed to fuel thousands of soldiers on the move with locally available grains and produce, supplemented by rations.
A New Understanding of the Roman Army
The comprehensive analysis of the Mursa mass grave serves as a powerful case study in how modern scientific techniques can illuminate the past. By integrating archaeology, radiocarbon dating, bioarchaeology, stable isotope analysis, and advanced genomics, the research team was able to reconstruct not just the final moments of these seven men, but also their life histories, origins, and diet. The study transforms our understanding from abstract historical accounts of battles into a tangible, human story about the individuals who lived and died in service to the empire.
Ultimately, the skeletons from the well in Mursa provide definitive proof of the diverse, non-local, and mobile character of the Roman legions during a period of profound crisis. They were not merely soldiers in a monolithic army, but individuals from different lands, brought together on a Croatian battlefield to fight and die in a Roman civil war, their shared fate preserved for nearly 1,700 years. Their story, unlocked by science, enriches and complicates our understanding of the very fabric of the Roman Empire.