The term European Banking Union refers to a common system of supervision and resolution of credit institutions at the level of the European Union, and was established in response to the financial crisis that arose in 2007 in the US real estate market and then spread to the rest of the world. Although the importance of supervision and the need for changes in fiscal policy at the level of the entire European Union were recognized even before the crisis, the crisis significantly highlighted the need to break the relations between the states and the credit institutions, where states help credit institutions in crisis situations, while using budgetary resources and thus endangering the security of citizens and the stability of the entire state. Due to the need to improve the financial supervision and better regulation of the banking system, the Banking Union was established in 2014 and operates in cooperation with the European Central Bank and the European System of Central Banks. It represents a comprehensive system aimed at better management and ensuring the stability of credit institutions, but also at protecting taxpayers. It is based on three pillars: the Single Supervisory Mechanism (SSM), the Single Resolution Mechanism (SRM) and the European Deposit Insurance Scheme (EDIS). The regulation of the European banking system is the responsibility of a special agency called the European Banking Authority, which aims to ensure the stable and transparent functioning of the banking system. The aim of this final paper is to explain the reason for the occurrence, importance and objectives of the European Banking Union and to analyse the success of supervisory activities of credit institutions in the European Union in the period from 2017 to 2019.