Did extreme climate conditions stimulate the migrations of the Germanic tribes in the 3rd and 4th centuries AD? An examination of historical data, climate proxy data, and migration events

Tree ring and palynological evidence suggests that drought in the third and fourth centuries AD may have been extreme enough to initiate migrations and invasions of the indigenous tribes of Germania. These movements and attacks strongly coincide with below mean tree-ring growth periods. The fourth century AD documentation records both prosperous and drought periods that correlate perfectly with the German oak and pine chronologies compiled from river valleys and archaeological sites. Additionally, these historical events are influenced by both political and military changes in Rome, but the role of climate change as inferred by the tree-ring chronologies appears to be significant. Climate anomalies are among many factors that may have perturbed the Germanic Tribes to the point of abandoning their ancestral homes and invading the Roman Empire.