Chapter 2 narrates the historical background, evolution, and context of Eurasian integration. The EAEU has been built upon previous integration entities, and the overview provides a better foundation for understanding EAEU’s legal nature and the institutional structure. It delimits the scope of Eurasian integration through an overview of various understandings of Eurasia and integration. It explains why the narrower conceptualization of Eurasian integration to delimitate as much as possible the boundaries of Eurasian integration by distinguishing stages and entities that led to EAEU-proper is preferred. It further establishes four relevant stages of Eurasian integration, which cover the period from the fall of the Soviet Union to our times and proceeds chronologically, starting with the early attempts to create a customs union in the post-Soviet space to establishing the EAEU itself. As there is no aim to provide a comprehensive overview of the history of Eurasian integration, it focuses primarily on its legal garment. It further provides an overview of the legal nature of the entities the EAEU has been built upon leading to an exploration of a prima facie legal nature of the EAEU.