The Eurasian Economic Union (EEU) has gone through some difficult and challenging times before reaching its current stage of development. The Customs Union (CU) and Common Economic Space (CES) between Russia, Belarus and Kazakhstan could be considered as the key elements of the EEU as a regional integration project. The first document, which might be called as the first prerequisite to create the CU, was the Agreement on the Customs Union signed by Belarus, Kazakhstan, and Russia on January 20, 1995.