On the effect of changes of rulers in Constantinople on the ruler’s position in neighbouring states based on two case studies concerning Bulgaria and Serbia

By comparing rulers? regnal dates among the Byzantines and their neighbours in Southeast Europe (Bulgaria, Croatia and Serbia), it is sometimes possible to establish that a change of ruler in Byzantium was closely followed (at a distance of around 1?3 years) by a change of ruler in a neighbouring region. This raises the question of whether there might be concrete or plausible clues in such a case that point to a connection between the two processes. Employing two examples, it is possible to demonstrate just how different the results of such an investigation can turn out to be.