The HERIDI project (EU Heritage Diplomacy and the Dynamics of Inter-Heritage Dialogue) opens new horizons in the research of new diplomacy by investigating a gap in current research: the uses of heritage in EU foreign policy and international cultural relations. The project explores these uses as EU heritage diplomacy. HERIDI scrutinizes EU heritage diplomacy simultaneously as it is being developed and implemented by various actors in EU member states and external countries. This data set focuses on the project's Work Package 2 (concept analysis of policy documentation). The data set includes documents authored by EU institutions: the European External Action Service, the European Commission, the European Parliament, the Council of the European Union, the European Economic and Social Committee, and the European Committee of Regions. The documents were found from the European Union's database EUR-Lex and ordered into thematic files based on their author and/or search terms: “cultur*”, “heritage”, “diplomat*”, “diplomacy”, "intercultural dialogue", "cultural institute", and "EUNIC". The data collection was conducted between 27 October and 16 November 2020. The data include 224 documents.