The history between the European Union and Russia has been one of interest for the entire world. With the growth in the relationship after the Cold War, it has become one exhaustive field of research and existing literature. Especially characteristic is the field which focuses on energy security and energy dependency and how these constitute the foundations of the relationship. Thus, this thesis follows how the economic relationship between the EU and Russia came to be developed from the dissolution of Soviet in 1922 up until today through a qualitative case study. This was done by starting the analysis with a portrayal of these thirty years and identifying which thematic components of the relationship that could be discerned as dominant and the causations of those. This was done especially in relation to energy as the relationship is largely characterized by energy interdependency. In relation to the components, issues as the challenges within the relationship, and how the actions performed by the EU was aligned with their own goals were discussed. The theoretical framework served as a fundamental part of the thesis, where a “taxonomy of power” was used to identify power structures which served as an explanation of understanding this historical relationship through economic means. Within the analysis it was then used further to find alignments to the traditional IR theories realism and liberalism. This combination of a taxonomy and theory gave opportunity to realize that theory at times certainly is limited and therefore contributed with a critical discussion too. The analysis showed that the relationship can be understood through three phases. The first shows alignment with the liberalist ideas as it focuses on institutional power, agreements, and interdependency right after the dissolution of the Soviet. The two latter, with the start from the Russian annexation of Crimea up until their invasion of Ukraine in February, alignment with realism as these focused on explicit forms of compulsory power as restrictive measures, productive power in using discourses, disinformation, and fears. Through these divisions the critical discussion of EU’s actions towards Russia questioned where the line should be drawn for continuing to rely on liberal values, cooperation and buying natural gas, despite it funding the Kremlins’ treasury.