The conference volume Transylvania in the Thirteenth to Sixteenth Centuries: Aspects of the Formation and Consolidation of Regional Identity is published as part of the European Science Foundation, EUROCORECODE Programme, Collaborative Research Project (henceforth abbreviated CRP), Cuius Regio: An Analysis of the Cohesive and Disruptive Forces Destining the Attachment of (Groups of) Persons to and the Cohesion within Regions as a Historical Phenomenon. This volume presents the internal results of the Romanian subproject hosted by the “1 December 1918” University of Alba Iulia. The successful operation of the project was made possible with the financial support offered by the Romanian Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI) through the contract for financing research activities no. 4EUROC/24. 08. 2010. The Romanian subproject aimed primarily at the investigation of one case study, focusing on regional development aspects in Transylvania, from the twelfth until nineteenth century in order to provide results necessary for the comparative approach proposed by the CRP. This volume is dedicated to the discussion of the medieval and late medieval issues. The papers included in this volume were organized chronologically and thematically. They are responding to specific questions in the Cuius regio questionnaire and each of them represents research that links the interests of the authors with the fundamental aspects addressed in the investigation of regional identities. The first four articles address various questions regarding the Transylvanian elites’ behaviour, from different perspectives, such as the role of elites in material culture transfers, the earliest stage of political activities of the local elites in the region’s congregations at the end of the thirteenth century, the Transylvanian nobility as bearers of regional identity in the fourteenth century, or the differences between the organization of the Transylvanian and the Middle Szolnok and Crasna counties. The next three articles approach questions about the region as a place of art production, art imports, or cultural influences in the case of Romanian and Saxon medieval churches. The final four articles deal with such topics as the foreign trade of Transylvania in the sixteenth century, the identity of Transylvania during the Ottoman-Habsburg competition for the control of the territory of Hungary in 1541-1551, and the border disagreements in the area of Bistrița and Maramureș in the sixteenth century. The last paper attempts to situate Transylvania within the broader context of the spread of the habit of smoking in Europe in the sixteenth and the seventeenth centuries. Keywords: European Science Foundation, EUROCORECODE programme, regional identity, Transylvania, medieval history