Language enthusiasts have been creating languages from scratch since at least the twelfth century: for fun, for secret communication with loved ones, in pursuit of the perfect language. Conlangs have surged in popularity in recent years thanks to films and TV series like Avatar (whose characters speak Na’Vi), Lord of the Rings (Elvish) and Game of Thrones; the grandaddy of pop-culture conlangs is Star Trek‘s Klingon, a widely studied language almost as popular as Esperanto ()

Meet David Peterson, who developed Dothraki for Game of Thrones