The first meeting of a new workshop on the History of Expressive Systems (HEX) is being held at ICIDS 2017. By 'expressive systems', we broadly mean computer systems (or predigital procedural methods) that were developed with expressive or creative aims; this is meant to be a superset of the areas called creative AI, expressive AI, videogame AI, computational creativity, interactive storytelling, computational narrative, procedural music, computer poetry, generative art, and more. While much of this purview intersects with projects in artificial intelligence, we are more broadly interested in procedural methods of all kinds (even predigital ones, as mentioned above).HEX is meant to illuminate and celebrate the history of systems in this area, especially the untold histories of projects that are today forgotten or relatively unknown. Most historical overviews of expressive systems in the literature today are confined to short blurbs in related-works sections, and upon further investigation these brief histories are often at best incomplete. For example, most accounts of the history of story generation cite Sheldon Klein's automatic novel writer [2] as the earliest known system (e.g., [1,6]), but in a recent paper undertaking the HEX initiative we have demonstrated that three other forgotten systems preceded Klein's [3].Why should we care about old, forgotten work? If we view expressive systems as a vast design space, we can think of each implemented system as an exploratory vessel that ventures into a previously uncharted sector. If these exploratory missions are successful, they signal directions that future systems may move further into to find greater success. When success is not had, the failed projects tell us which areas to avoid. In this way, we learn about spaces that incrementalist research may push further into, dead sectors that we should not return to, and all the other still uncharted areas that we do not know much about at all. Thus, both good and bad systems generate new knowledge that is useful to contemporary and future practitioners. But when we forget about past systems-novel explorations in design space-we lose the knowledge that was generated by those systems: we forget what has been explored and what has not, and which areas are worth exploring further. In our own historical re-