Veroli is a town and comune in the province of Frosinone, Lazio, central Italy, in the Latin Valley. Veroli became a Roman municipium in 90 B…Veroli is a town and comune in the province of Frosinone, Lazio, central Italy, in the Latin Valley. Veroli became a Roman municipium in 90 BC. It became the seat of a bishopric in 743 AD, and was occupied by Spanish soldiers, allied to the Colonna family, in the 16th century.