Pre-Slavic Period (until 958)
As far as we know, Bosnia has been inhabited at least since Neolithic times, then inn the late Bronze Age, the Neolithic population was replaced by Illyrians. In the 4th and 3rd century BCE, Celtic migrations displaced many Illyrian tribes from their former lands, but some Celtic and Illyrian tribes mixed.
Conflict between the Illyrians and Romans started in 229 BCE, but Rome wouldn’t complete its annexation of the region until 9 CE and Roman soldiers were encouraged to retire in the region.
By the end of the 1st century, Christianity had already arrived in the region and there are
quite a few artifacts from the time to prove it.
The region was conquered by and further exchanged hands between the Western Roman Empire, Ostrogoths, the Alans and Huns in the years to follow. By the 6th century, the area was re-conquered for the Byzantine Empire. The Slavs, (migratory people from southeastern Europe) settled in what is now Bosnia and Herzegovina.