 The Roman levy of 403 BC was the first to be requested to campaign for longer than a single season, and from this point on such a practice became gradually more common, if still not typical.A small navy had operated at a fairly low level after the Second Samnite War, but it was massively upgraded during this period, expanding from a few primarily river- and coastal-based patrol craft to a full maritime unit.After a period of frenetic construction, the navy mushroomed to a size of more than 400 ships on the Carthaginian pattern.