Career Behaviour and the European Parliament seeks to answer the question of how a political institution, such as the European Parliament, can impact the career ambitions and behaviours chosen by European politicians.Long considered a ‘second order’ legislature in its degree of political importance and prestige, the European Parliament is the only directly elected institution within the European Union and is an increasingly important part of the European legislative process. Using a major new source of quantitative data and interviews with more than 50 current and former European legislators, this book argues that as the institution has become increasingly professionalized and powerful, the volatility of its membership has declined. However, the professional ambitions of its members vary greatly by national background, leading to an uneven distribution of legislative seniority and influence within the legislature. The book presents a new theory with political careers acting as institutions in themselves, and also offers complete background information on all elected Members of the European Parliament, from 1979-2014.