Demography and Life Histories across the Roman Frontier in Southern Germany 400-700 CE

AI interpretationAI-generated

Ancient DNA from 258 people reveals how Roman frontier society became early medieval Central Europe.

This study sequenced 258 ancient genomes from southern Germany's old Roman frontier, spanning 400-700 CE, and compared them with 2,500 ancient and 379 modern genomes. After Roman state structures collapsed in the late fifth century, a northern European founding group mixed with genetically diverse Roman provincial populations. Intermarriage was widespread and cultural differences were minimal. Genetic structure lasted through the sixth century, and by the early seventh century admixture had produced a population resembling modern Central Europeans.

• A major demographic shift followed the late fifth-century collapse of Roman state structures, when a northern European ancestry group mixed with diverse Roman provincial groups.
• Pedigree reconstruction shows widespread intermarriage, minimal cultural differentiation, and genetic structure persisting through the sixth century before forming a modern Central European-like population by the early seventh century.
• Estimated generation time was 28 years, life expectancy was 39.8 years for women and 43.3 for men, infant mortality was high, and nearly one quarter of children lost at least one parent by age 10.

Sample interpretation

The 258 sampled genomes come mainly from Altheim (110), Büttelborn (40), Mömlingen (28), Straubing Azlburg (17), and Weilheim (13), with smaller groups from other sites. Y-chromosome lineages were resolved for 129 individuals; the most frequent are E-BY35788 (15), I-PH1176 (7), and E-A8612 (5). Common mitochondrial haplogroups include H2a (10), T2b2b (8), U5a1a2a1 (7), and J1c2o1 (7).

For genealogy enthusiasts

For ancestry enthusiasts, this shows that early medieval Central European ancestry formed through small-group mobility, intermarriage, and admixture after Roman collapse, not only large-scale migrations. It also links genetic change to family structure, monogamy, and life history in the Roman frontier.