High Quality Content by WIKIPEDIA articles! Unlike the other three "classical" prefectures that are mentioned in the Notitia Dignitatum (Gaul, Italy-Africa and the East), the early administrative history of Illyricum during the 4th century was turbulent, as it was abolished, re-established and divided several times. Initially the territories comprising the later prefecture belonged to the central Prefecture of Italy, Illyricum and Africa, when it was established in 337 following the division of the Empire among the sons of Constantine the Great. It seems that the three dioceses of Macedonia, Dacia and Pannonia were first grouped together in a separate praetorian prefecture in 357 by Constantius II. It remained in existence until 361, when it was abolished by emperor Julian, and then existed again from 375-379 under Gratian.[