https://en.wikipedia.org/wiki/History_of_Serbia
The Paleo-Balkan tribes formed in the 2nd and 1st millennia BC. The northernmost Ancient Macedonian city was in south Serbia (Kale-Krševica).The Celtic Scordisci tribe conquered most of Serbia in 279 BC, building many forts throughout the region. The Roman Empire conquered the region in the span of 2nd century BC – 1st century AD. The Romans continued the expansion of …