Revisiting early medieval chronologies: radiocarbon dates reveal the origins and history of the Carolingian-age Great Moravian hillforts

Abstract This article examines the chronology of Great Moravian hillfort construction using radiocarbon data from the Bojná agglomeration, one of the key centres of early medieval settlement in the Middle Danube Basin. Based on an analysis of 79 radiocarbon dates from five sites, a refined chronological model is proposed for the agglomeration’s development in the 6th–10th centuries. The findings challenge the widely accepted view that hillfort construction intensified only at the turn of the 8th and 9th centuries. The data presented here are expected to stimulate broader critical discussion on the chronology of Carolingian-period hillfort construction in Central Europe. The modelling has also revealed a significant issue: radiocarbon dates associated with features from the first half of the 9th century tend, once calibrated, to extend back into the 8th century—a pattern that is not supported by the existing archaeological evidence. This discovery highlights a challenge for archaeologists, as it may result in the false ageing of features and distort the broader chronological framework. This would indicate a more general problem within early medieval archaeology, particularly concerning the chronology of the Carolingian period. Identifying this issue here may help direct future research efforts towards resolving it.