Drought encouraged Attila’s Huns to attack the Roman empire, tree rings suggest
Spatial agreement between reconstructed and measured European summer drought. High-resolution, 0.5° spatial correlation coefficients (color scale) between the tree-ring stable isotope (TRSI) proxy record and the gridded European-wide self-calibrated Palmer Drought Severity Index (scPDSI) target data calculated over the common period 1901–2018 CE. (Created by Ulf Büntgen.). Credit: Journal of Roman Archaeology (2022). DOI: 10.1017/S1047759422000332…