Stable strontium isotopes in human teeth and bone: a key to migration events of the late Roman period in Bavaria

After the Romans had left their former province Ractia II (today southern Bavaria) in AD 488, the hitherto unknown tribe of baiovarii (Bavarians) was first recorded in AD 551. Current archaeological theory claims that this tribe was founded by native Celts, Roman populations, and Germanic mercenaries previously recruited by the Roman military. The geochemical diversity of Bavaria permits the application of Sr isotope analyses for the reconstruction of migration events. Analysis of tooth/bone pairs of 70 individuals from a burial site associated with a Roman fortress revealed that 30% of the dead were primarily non-local to thee Roman province but originated from north-eastern areas. A relatively higher number of female immigrants was identified which is best explained by exogamy. Serial analyses of complete dentitions revealed that several males had entered the province as small children and thus cannot have been recruited mercenaries. Such a definition of the ontogenetic stage of an individual at the time of its residence change offers new perspectives for the evaluation of migration events in the past. (C) 2003 Elsevier Ltd. All rights reserved.