Complex sentence: The town was known as "Rigomagensium" under the Roman Empire and was the capital of a civitas (a provincial subdivision), though no Roman money has yet been found in the canton of Barcelonnette.
Split into simpler sentences: The town was known as "Rigomagensium" under the Roman Empire and was the capital of a civitas (a provincial subdivision). No Roman money has yet been found in the canton of Barcelonnette.