The presentation focuses on the German concept of constitutional identity. The first part describes the historical background and development briefly. Secondly, the constitutional identity doctrine, as developed by the German Constitutional Court in its famous Lisbon judgment and later decisions, is described. The final part analyses the German concept of constitutional identity. It will be argued that even though the German concept can be criticised as a too creative judicial concept, it is as such a legitimate constitutional doctrine as its ultimate purpose is to protect the core principles, respectively, the content of the German constitution.