The Essential Guide to Episode I was a trade paperback Essential Guide that was intended to delve into the story, individuals, and universe of Star Wars: Episode I The Phantom Menace. Dan Wallace was slated to be its author, and it was at one time known as The Ultimate Guide to Episode I. Its publication was scrapped because it became apparent that interest in Episode I merchandise had waned significantly, and that content from Attack of the Clones, Revenge of the Sith, and Expanded Universe works, including the Clone Wars multimedia initiative and the New Jedi Order series, would offer more material than a single book could contain. Consequently, the Essential Guide series was rebooted, starting with The New Essential Guide to Characters in 2002. This title, together with The New Essential Guide to Vehicles and Vessels, The New Essential Guide to Weapons and Technology, The New Essential Guide to Droids, and The New Essential Guide to Alien Species, are some of the publications that incorporated details initially intended for this never-released book.