This edited collection, in honour of the late political scientist Peter Mair, contains original chapters that are directly linked to his theoretical and/or methodological ideas and approaches. Peter Mair demonstrated that political parties have traditionally been central actors in European politics and an essential focus of comparative European political science. Though the nature of political parties and the manner in which they operate has been subject to significant change in recent decades, parties remain a crucial factor in the working of European liberal democracies. This volume analyses recent developments and current challenges that European parties, party systems and democracy face. The volume will be of key interest to students and scholars of comparative politics, democracy studies, political parties, and European politics and European Union studies.