Party literature is largely focused on the rise and success of new parties and their effects on party systems and older parties. This book, on the other hand, provides a valuable and original addition to such literature by analyzing what happens to a party when it enters government for the first time. Leading contributors assess how these parties, whether old or new, change when entering government by answering a set of questions: How and why has their role changed? What are the consequences of change? What explains the evolution from principled opposition to loyal opposition and eventually to participation in the executive? Which characteristics of the parties can be held responsible? Which characteristics of the parties’ context should be brought into the picture? What have been the effects of the status change on party organization, party ideology and electoral results? Covering a wide range of European parties such as the Finish Greens, right wing parties (FN, Lega Nord and Alleanza Nazionale) and new parties in Italy , The Netherlands and Sweden to name a few; this book will be of particular interest to scholars and students concerned with party systems, political parties and comparative politics.