The integration of information systems (IS) is a phrase which is commonly used in both research and practice within the IS field and across many organizational contexts. This paper uses a historical review to explore how the image of integrated IS has been constructed, evolved over three decades and how this has resulted in the widespread acceptance of idealized goals and benefits. A literature search for an underlying theoretical basis for the concept of systems integration is made, highlighting a diversity of opinion. Two case studies are used to examine the meaning of integration relative to the images and ideals, theory and reality. The study concludes that there is an urgent need for better conceptual and theoretical models of integration to enable more effective discourse of the concept. These models must also encompass and include more diverse non-technical factors for the adoption of more complex forms of IS.