This paper raises methodological issues of radiocarbon (14C) dating of historical events based on data obtained during the excavations of the Russian medieval city of Yaroslavl. The city is of special interest to our study because of the precise time of its destruction by troops of Batu Khan mentioned in chronicles—the winter of 1238. To date in Yaroslavl, researchers have discovered 9 mass burials of citizens and domestic animals buried sometime after the massacre by the Mongols. Mass burials of people alongside animals in a common grave and outside of the cemetery, in violation of Christian traditions, are not typical of medieval Russia and are a sign of a military catastrophe. To test this hypothesis, we dated a total of 65 samples representing all 9 mass burials. A Bayesian chronological model of the accelerator mass spectrometry (AMS) dates narrowed the interval to the range of 1197–1280 cal AD, with the mean age of 1239 AD, consistent with the hypothesis that the studied mass burials of citizens and livestock are related to the capture of the city by the army of Batu Khan.

This fifth date list for the long cultural sequence in El Mirón Cave (Cantabria, Spain) reports on new radiocarbon assays for the Middle Paleolithic and Lower Magdalenian levels, ranging from about >45 to 15 uncalibrated kyr.