Germania and Climate Variability in 3rd and 4th Centuries A.D.: A Methodological Approach to Dendroclimatology and Human Migration

Abstract

This study compared the timing of migrations of the Germanic tribes and the incremental growth rates of trees in Central Europe from the 3rd and 4th century A.D. It has been suggested that the Germanic tribes were not influenced by climate change; however, this study of climate data found coincidence between low-growth periods in trees and human activity among the Germanic tribes. A network chronology, compiled from cross-dateable regional master oak and pine tree-ring chronologies, reveals periods of low and high growth rates in trees that can be indicative of paleoclimates. Tribal activity was defined by contemporaneous documentation of attacks, incursions, migrations, and evidence of new or abandoned settlements where dates are known or widely accepted. The co-occurrence frequency between low-growth years as evident in trees and tribal activity was high, at 74% for all 201 years (136 events) and 97% from the years A.D. 269 to 374 (61 events). The findings of this study may help understand the various events and motivations of the Germanic tribes in the 3rd and 4th centuries A.D., and, minimally, should reinstate climate as an influence to migration.