Complex sentence: Year 346 BC was a year of the pre-Julian Roman calendar.In the Roman Empire it was known as the Year of the Consulship of Corvus and Visolus (or, less frequently, year 408 "Ab urbe condita").
Split into simpler sentences: Year 346 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Corvus and Visolus (or, less frequently, year 408 "Ab urbe condita").