The city population was very diverse. Engravings on tombstones suggest that only a minority of the population came from Italy, while many veterans were from Dalmatia, South Gaul and Syria. Because of the ethnic diversity of the population, Latin maintained itself as the main language in the city at the expense of Greek, which was spoken in most of the Moesian and Macedonian cities. During the following centuries, Scupi experienced prosperity. The period from the end of the 3rd century to the end of the 4th century was particularly flourishing. A first church was founded under the reign of Constantine the Great and Scupi became the seat of a diocese. In 395, following the division of the Roman Empire in two, Scupi became part of the Eastern Roman Empire.