Emotional intelligence (EI) has undergone significant theoretical evolution since its introduction. This article provides a comprehensive historical review of EI, focusing on major models such as the ability model by Salovey and Mayer, Goleman's mixed model, Bar-On's social-emotional framework, and the trait model developed by Petrides. The review discusses how these models differ in definitions, assessments, and theoretical scope, while also noting the global parallels in philosophical traditions that echo EI principles. Although fragmented, the field of EI is maturing through integrative frameworks that align emotional skills with broader psychological constructs. The article concludes by highlighting the current challenges and directions in refining EI as a valid construct for research and application.