Complex sentence: The Romans called the town "Bovianum Vetus", The early role of "Bovianum Vetus" is little known, it was a center of vital importance, when the Romans conquered the Samnites, and Pietrabbondante became a place of reference for checking the Alto Molise.
Split into simpler sentences: The Romans called the town "Bovianum Vetus", the early role of which is little known. It became, however, a center of vital importance; when the Romans conquered the Samnites, Pietrabbondante became a place of reference for checking the Alto Molise.