The city was founded by Emperor Justinian I. It existed from the 530s to 615 and was designed as a splendid bishop's seat. The city was a completely new foundation in honour of the nearby village of Tauresium, the birthplace of Justinian. According to Procopius Bederiana, the birthplace of Justinian's uncle and mentor Justin I was nearby. There has been a long debate about the identification of these historical places. The huge correlation between the archaeological site and the description by Procopius as well as finds of seals of the bishop of Iustiniana Prima are strong arguments for an identification of Justiniana Prima with Caričin Grad. The city planning combined classical and Christian elements: thermae, a forum, and streets with colonnades. Typical Mediterranean features went along with numerous churches. Justinian himself ordered the foundation of the cityby law in 535, establishing the Archbishopric of Justiniana Prima, making it at the same time the capital of the prefecture of Illyricum instead of Thessaloniki. It also was chosen as the seat of the Dacian diocese. Thessaloniki, however, did not actually lose much of its administrative functions during the short lifetime of Justiniana Prima. Still, the new foundation was not without importance and Justinian made sure that this city, which was one of his favourite projects, received all the necessary support. In 545 Justinian issued another law underlining the episcopal rights and status of Justiniana Prima, which is also confirmed by letters that were exchanged between Justinian and Pope Gregory I at the end of the 6th century. The town was abandoned at around 615. Invading Avars coming from north of the Danube may be one factor, missing political interest in the town after the time of Justinian may be another. Among many other imported finds the presence of 2 pieces of a specific type of fibulae and handmade pottery have been understood as an indication of the presence of Slavs already before the Avar incursion.
Archaeological site
There have been archaeological excavations for nearly 100 years with the participation of French and more recently also German researchers. There is a permanent exhibition in the national museum in Leskovac. At the site itself monuments there are impressive remains of the fortification, the acropolis as well as of several churches and many other buildings.