The town was named Navissos, by the Celtic masters of the city in the 3rd century BC ! It was then known as Naissus in Greek.Today in Slavic as Nis a town in Serbia!
A city of great historical importance, Naissus is best known as the birthplace of Emperor Constantine the Great. This ancient city of the Balkans was an established trade route where many cultures came into contact. The Naissus Molossus was probably a result of crossing Roman and Greek mastiffs with the Balkan sheepdogs. Used for herding, guarding, hunting and baiting duties, this colossal breed is believed to had become extinct during the early years of the 19th century.
There is also a theory suggesting that the Naissus dog found its way into the bloodline of another extinct Molosser, the Russian Medelyan Mastiff.
The scarce information concerning the Naissus mastiff reveals only that the dog was "...a canine Goliath, standing 40 inches tall, differing from the bears it fought only by its white chest and tiger fur...", apparently hinting that it was brindle with white markings. There are some dogs today in the region that are sometimes presented as being the Naissus Molossus, but these are in essence just Sarplaninac crosses.