Europe's sovereign debt crisis and the accompanying national bank crises in the European Union brought bank regulation and supervision to the top of the EU policy agenda. In a few short years, we have witnessed a 'great leap forward' for European integration marked by over a dozen pieces of EU legislation shaping the operation of banks, rules on bank capital, reconfigured supervisory agencies, and Banking Union. This book addresses three political battles behind the adoption of these new policies: divisions among states; national vs. supranational jurisdiction; and the conflictual process of policy. This book was originally published as a special issue of West European Politics.