Iustiniana Prima, or Caričin Grad (Empress’s Town), is one of the most important Byzantine towns in the interior of the Balkan peninsula. It is situated 29 km west of Leskovac, 7 km from Lebane, close to the village of Prekopčelica, where the Caričina river flows into the Svinjarica. Emperor Justinian I, originally from southern Serbia, decided to raise a city in his area of birth in honour of his own name. The city of Justiniana Prima lies on the gentle slopes which descend from the mountain of Radan towards the Leskovac basin, where key traffic routes pass.

It was built on a plateau which ends with a rocky terrace at the confluence of the two small rivers. It was founded by Justinian I in the 6th century at the site of the local fortress of Bederiana. This is supported by the remains of a monumental basilica in the lower town, bearing an authentic monogram of Justinian and a large episcopal basilica on the acropolis. Besides secular structures, a total of ten basilicas have been found.

Caričin Grad is an exceptional monument to classical urbanism and architecture. The ruins of a fortification, streets with porticos, basilicas, public and private structures, walls, a water supply system with aqueduct and large cistern and floor mosaics in lavish structures all contribute to a picture of the city and are a reflection of the achievements of early Byzantine civilization, founded on the Graeco-Roman tradition.

After frequent incursions by the Avars and the infiltration of the Slavs around 615, the town was abandoned by its native population; life in the city dwindled to nothing, probably due to fires or the interruption of the water supply during the final sieges.