Volume 4-5 is dedicated to the 90th anniversary of Prof. Dr. Vassilka Tapkova-Zaimova, the doyen of Bulgarian Balkan, Byzantine and Medieval Studies. It mainly contains papers presented at the confer cnct Medieval Bulgaria in the context of Balkan and European history and culture, which was dedicated to the jubilarian and was held on 28 February 2014 in different rooms of Sofia University “St. Kliment Ohridski”. The issue of this volume, which is implemented with the moral and financial support of the Association of the Byzantinists and Medievalists in Bulgaria, is a testament to the respect of the members of that organization to its honorary chairwoman.