It belonged to the Delian League since it appears in the Athens tribute register of 422/1 BCE.
[2] Tragilus's coins from the 5th century BCE, with the inscription «ΤΡΑΙ» or «ΤΡΑΙΛΙΟΝ», are also preserved.
[3] In addition, it is documented in the theorodokos list of Epidaurus of the year 360/59 BCE.
[5] In the Peutinger Table there is a place "Triulo" marked as 10 miles from Philippi, which is apparently a corruption of the name form "Traelio" similar to the coin inscriptions «ΤΡΑΙΛΙΟΝ».
It was the place of origin of Asclepiades of Tragilus, a mythographer of the fourth century BCE.