This open access book of a collective volume offers a comprehensive understanding of political polarization and its implications for democracy. The recent revival of the concept in political debates and academic literature reflects growing concerns about how polarized societies affect democratic norms. In increasingly divided environments, opposing camps express mutual distrust or even hostility, fuelling the rise of extremist parties, hate speech, and anti-political sentiment. Based on a funded research project ( Hellenic Foundation for Research and Innovation (H.F.R.I.) Project No 4527) the volume develops a theoretical and methodological framework to explore how oppositions are constructed across different actors and levels, contributing to an integrated and comprehensive approach of political polarization enriching the study of political competition and cleavages in Greece, while also offering insights of broader comparative and international significance . Internationally, studies on political polarization are reviving but remain fragmented across disciplines. In Greece, systematic interdisciplinary research has been scarce. This volume bridges that gap by integrating political science, sociology, and communication, analyzing the shift from issue-based to affective polarization through mixed qualitative and quantitative methods. Focusing on the profoundly polarizing decade between 2010 and 2020 , the book situates polarization within multiple overlapping crises-the debt crisis , the refugee crisis , democratic backsliding , the COVID-19 pandemic , and the Prespa Agreement . These crises redefined the socio-political landscape intensifying existing divisions and generating new lines of conflict: memorandum versus anti-memorandum, pro versus anti-immigration, pro versus anti Europe and nationalist versus cosmopolitan identities. By analyzing how antagonistic narratives construct enemies -political opponents, minorities, or external actors like the EU-as threats to national, economic, or cultural stability, the volume demonstrates how such rhetoric fuels polarization . This process solidifies in-group and out-group dynamics deepening affective polarization. This book addresses scholars, policymakers, and engaged citizens seeking to understand how historical, cultural, and institutional dynamics shape contemporary political conflicts in Greece and comparable contexts.