The name and the verses of Phaedrus were unknown in the Middle Ages but his fables were widespread in several prosified versions. One of these is the collection of Romulus, which is of great importance because it has preserved some lost Phaedrian fables and various other collections have derived from it. This paper examines the textual tradition of these and of Phaedrus’ fables. I attempt to present some problems about the tradition and offer a solution to these questions.